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BEGIN:VEVENT
SUMMARY:Locating the critical end point of QCD
DTSTART;VALUE=DATE-TIME:20160725T172500Z
DTEND;VALUE=DATE-TIME:20160725T174500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2725@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Christian Fischer (JLU Giessen)\nI will give an over
view on our recent results for the phase\ndiagram of QCD with Nf=2+1 and N
f=2+1+1 flavors. We use a combination\nof lattice and Dyson-Schwinger meth
ods to determine the chiral\nand deconfinement order parameters at finite
temperature and chemical \npotential. In a recent exploratory study we als
o give a first estimate \non the influence of baryon effects on the locati
on of the critical \nend-point. As a result we find a critical end-point a
t large chemical \npotential in the vicinity of the chiral critical line e
xtrapolated from\nlattice QCD.\n\nhttps://conference.ippp.dur.ac.uk/event/
470/contributions/2725/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2725/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lefschetz-thimble approach to the Silver Blaze problem of one-site
fermion model
DTSTART;VALUE=DATE-TIME:20160727T082000Z
DTEND;VALUE=DATE-TIME:20160727T084000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2724@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Yuya Tanizaki (RIKEN BNL Research Center)\nPath inte
gral on Lefschetz thimbles gets much attention in the context of the sign
problem\, because of its usefulness in order to study the system with the
complex classical action nonperturbatively. After giving its brief introdu
ction\, it is applied for studying the sign problem of the one-site Hubbar
d model. This model has a severe sign problem\, which looks quite similar
to that of the finite-density QCD at low temperatures. We present the anal
ytical study of the sign problem using the Lefschetz-thimble method\, and
also discuss the failure of the complex Langevin method. Furthermore\, we
give a speculation about the early-onset problem of the baryon number dens
ity\, called the baryon Silver Blaze problem\, based on similarity between
the sign problems of one-site Hubbard model and of finite-density QCD.\n\
nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2724/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2724/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of the phase diagram of dense QC$_2$D with $N_f=2$ within la
ttice simulation
DTSTART;VALUE=DATE-TIME:20160728T161000Z
DTEND;VALUE=DATE-TIME:20160728T163000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2712@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Aleksandr Nikolaev (ITEP)\nIn this talk we present o
ur results on the low-temperature scan of the phase diagram of dense two-c
olor QCD with $N_f=2$ quarks. The study is conducted using lattice simulat
ion with rooted staggered quarks. At small chemical potential we observe t
he hadronic phase\, where the theory is in a confining state\, chiral symm
etry is broken\, the baryon density is zero and there is no diquark conden
sate. At the critical point $\\mu = m_{\\pi}/2$ we observe the expected se
cond order transition to Bose-Einstein condensation of scalar diquarks. In
this phase the system is still in confinement in conjunction with non-zer
o baryon density\, but the chiral symmetry is restored in the chiral limit
. We have also found that in the first two phases the system is well descr
ibed by chiral perturbation theory. For larger values of the chemical pote
ntial the system turns into another phase\, where the relevant degrees of
freedom are fermions residing inside the Fermi sphere\, and the diquark co
ndensation takes place on the Fermi surface. In this phase the system is s
till in confinement\, chiral symmetry is restored and the system is very s
imilar to the quarkyonic state predicted by SU($N_c$) theory at large $N_c
$.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2712/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2712/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roberge-Weiss transition in Nf=2 QCD with staggered fermions and N
t=6
DTSTART;VALUE=DATE-TIME:20160725T160500Z
DTEND;VALUE=DATE-TIME:20160725T162500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2710@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Alessandro Sciarra (Goethe Universität)\nThe QCD ph
ase diagram at imaginary chemical potential exhibits a rich structure and
studying it\ncan constrain the phase diagram at real values of the chemica
l potential. Moreover\, at imaginary\nchemical potential standard numeric
techniques based on importance sampling can be applied\, since \nno sign p
roblem is present.\n\nIn the last decade\, a first understanding of the QC
D phase diagram at imaginary chemical potential\nhas been developed\, but
it is so far based on investigations on coarse lattices ($N_t=4\,\\\;a=0.3
$ fm).\nConsidering the $N_f=2$ case\, at the Roberge-Weiss critical value
of the imaginary chemical potential\,\nthe chiral/deconfinement transitio
n is first order for light/heavy quark masses\nand second order for interm
ediate values of the mass: there are then two tricritical masses\, whose\n
position strongly depends on the lattice spacing and on the discretisation
. On $N_t=4$\, we have the chiral \n$m_{\\pi}^{\\mbox{tric.}}\\simeq400$ M
eV with unimproved staggered fermions and $m_{\\pi}^{\\mbox{tric.}}\\simeq
900$ MeV with unimproved pure Wilson fermions.\n\nEmploying finite size sc
aling we investigate the change of this tricritical point between $N_t=4$
and $N_t=6$\nas well as between Wilson and staggered discretisations.\n\nh
ttps://conference.ippp.dur.ac.uk/event/470/contributions/2710/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2710/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Scalar QCD at nonzero density
DTSTART;VALUE=DATE-TIME:20160729T142000Z
DTEND;VALUE=DATE-TIME:20160729T144000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2708@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jacob Wellnhofer (Universität Regensburg)\nWe study
scalar QCD at nonzero density in the strong coupling limit. \nIt has a si
gn problem which looks structurally similar to the one in QCD.\nAfter intr
oducing dual variables by integrating out the SU(3) gauge links\nwe find t
hat we need at least 3 flavors for a nontrivial dependence on the \nchemic
al potential. \nIn this dual representation there is no sign problem remai
ning. \nThe dual variables are partially constrained\, \nthus we use a hyb
rid approach for the updates: \nFor unconstrained variables we use local u
pdates\, \nwhile for constrained variables we use updates based on the wor
m algorithm.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/
2708/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2708/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Testing dynamic stabilization in complex Langevin simulations
DTSTART;VALUE=DATE-TIME:20160726T132000Z
DTEND;VALUE=DATE-TIME:20160726T134000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2702@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Benjamin Jaeger (Swansea University)\nComplex Langev
in methods have been successfully applied in theories that suffer from a s
ign problem such as HDQCD. We present and illustrate a novel method that e
nsures that Complex Langevin simulations stay close to the SU(3) manifold\
, which lead to correct and improved results in the framework of HDQCD and
pure gauge simulations. Applying the same technique in fully dynamical QC
D simulations shows great potential to allow the determination of the phas
e diagram from first principles.\n\nhttps://conference.ippp.dur.ac.uk/even
t/470/contributions/2702/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2702/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Complex spectrum of spin models for finite-density QCD
DTSTART;VALUE=DATE-TIME:20160727T092000Z
DTEND;VALUE=DATE-TIME:20160727T094000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2699@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Hiromichi Nishimura (RIKEN BNL Research Center)\nWe
consider the spectrum of transfer matrix eigenvalues associated with Polya
kov loops in lattice QCD at strong coupling. The transfer matrix at finite
density is non-Hermitian\, and its eigenvalues become complex as a manife
station of the sign problem. We show that the symmetry under charge and co
mplex conjugations ensures that the eigenvalues are either real or part of
a complex conjugate pair\, and the complex pairs lead to damped oscillato
ry behavior in Polyakov loop correlation functions\, which also appeared i
n our previous phenomenological models using complex saddle points. We arg
ue that the results reflect oscillatory behavior in color-charge densities
and it should be observable in lattice simulations of QCD at finite densi
ty.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2699/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2699/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anderson localisation of Dirac eigenmodes in high temperature QCD
DTSTART;VALUE=DATE-TIME:20160729T142000Z
DTEND;VALUE=DATE-TIME:20160729T144000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2695@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Guido Cossu (Higgs Centre for Theoretical Physics\,
School of Physics and Astronomy\, University of Edinburgh)\nWe investigate
the properties of the background gauge field configurations that act as d
isorder for the Anderson localization mechanism in the Dirac spectrum of Q
CD at high temperatures. We compute the eigenmodes of the M\\"obius domain
-wall fermion operator on configurations generated for the $SU(3)$ gauge t
heory with two flavors of fermions\, in the temperature range $[0.9\,1.9]T
_c$. We identify the source of localization of the eigenmodes with gauge c
onfigurations that are self-dual and support negative fluctuations of the
Polyakov loop $P_L$\, in the high temperature sea of $P_L\\sim 1$. The dep
endence of these observations on the boundary conditions of the valence op
erator is studied. We also investigate the spatial overlap of the left-han
ded and right-handed projected eigenmodes in correlation with the localiza
tion and the corresponding eigenvalue. We discuss an interpretation of the
results in terms of monopole-instanton structures.\n\nhttps://conference.
ippp.dur.ac.uk/event/470/contributions/2695/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2695/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gauge cooling for the singular-drift problem in the complex Lange
vin method - an application to finite density QCD
DTSTART;VALUE=DATE-TIME:20160726T165000Z
DTEND;VALUE=DATE-TIME:20160726T171000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2693@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Keitaro Nagata (KEK)\nThe complex Langevin method is
a promising approach \nto complex action systems\, which suffer from the
sign problem.\nIn particular\, the use of gauge cooling enabled the studie
s of finite \ndensity QCD either in the deconfined phase or in the heavy d
ense limit. \nIn the confined phase with light quarks\, however\, the meth
od does not\nwork as it is due to the singularities in the fermion drift t
erm\ncaused by small eigenvalues of the Dirac operator with the quark mass
.\nIn a previous paper\, we proposed that this singular-drift problem \nca
n be overcome by the gauge cooling with different criteria for choosing \n
the complexified gauge transformation\, and showed that\nthe method works
in chiral Random Matrix Theory even at small quark mass. \nHere\, we apply
the same idea to QCD at finite density with light quarks \nand present so
me preliminary results.\n\nhttps://conference.ippp.dur.ac.uk/event/470/con
tributions/2693/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2693/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Results on the heavy-dense QCD phase diagram using complex Langevi
n
DTSTART;VALUE=DATE-TIME:20160726T130000Z
DTEND;VALUE=DATE-TIME:20160726T132000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2670@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Felipe Attanasio (Swansea University)\nComplex Lange
vin simulations have been able to successfully reproduce results from Mont
e Carlo methods in the region where the sign problem is mild and make pred
ictions when it is exponentially hard. We present here our study of the QC
D phase diagram in the limit of heavy and dense quarks (HDQCD) for 3 diffe
rent lattice volumes and the boundary between the hadronic phase and the q
uark-gluon plasma. We also briefly discuss instabilities encountered in ou
r simulations.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contribution
s/2670/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2670/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Abelian color cycles: a new approach to strong coupling expansion
and dual representation for non-abelian lattice gauge theory.
DTSTART;VALUE=DATE-TIME:20160729T163000Z
DTEND;VALUE=DATE-TIME:20160729T165000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2667@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Carla Marchis (University of Graz)\nWe present a dua
l approach for SU(2) lattice gauge theory\, i.e.\, an exact mapping of the
partition sum to new\, so-called dual variables. The dual representation
is constructed by decomposing the Wilson gauge action into “abelian colo
r cycles” (ACC)\, which are loops in color space around plaquettes. The
ACCs are complex numbers and as such commute\, such that a dual representa
tion can be obtained as in the abelian case. The original SU(2) degrees of
freedom are integrated out and the dual degrees of freedom are occupation
numbers of the ACCs\, subject to constraints reflecting the original SU(2
) symmetry.
The approach is then extended to the case of SU(2) gauge fi
elds with fermions. Analyzing the strong coupling region we show that the
system is free of sign problems up to $O(\\beta^3)$. The ACC concept can b
e generalized to other non-abelian gauge groups such as SU(3).\n\nhttps://
conference.ippp.dur.ac.uk/event/470/contributions/2667/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2667/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Temperature dependence of shear viscosity in SU(3)-gluodynamics
DTSTART;VALUE=DATE-TIME:20160729T165000Z
DTEND;VALUE=DATE-TIME:20160729T171000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2660@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Victor Braguta (ITEP)\nThis report is devoted to the
study of temperature dependence of shear viscosity in SU(3)-gluodynamics.
\nTo calculate shear viscosity we measured the correlation function of th
e energy-momentum tensor\nT_{12}T_{12} for a set of temperatures in the re
gion T/T_c \\in (0.9\, 1.5). The measurements \nwere carried out using mu
ltilevel algorithm which considerably improves the accuracy \nof the data.
The results of the calculation allow to determine temperature dependence
of \nthe ratio of shear viscosity to the entropy density {\\eta}/s.\n\nhtt
ps://conference.ippp.dur.ac.uk/event/470/contributions/2660/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2660/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Precision test of the gauge/gravity duality in two-dimensional N=(
8\,8) SYM
DTSTART;VALUE=DATE-TIME:20160729T144000Z
DTEND;VALUE=DATE-TIME:20160729T150000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2657@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Daisuke Kadoh (Keio Univ.)\nWe present a precision t
est of the gauge gravity duality in two-dimensional N=(8\,8) SYM. We emplo
y the Sugino lattice action to perform lattice simulations of N=(8\,8) SYM
at finite temperature. We show the evidence of validity of the duality co
njecture by comparing lattice results with analytical predictions of the c
orresponding gravitational theory.\n\nhttps://conference.ippp.dur.ac.uk/ev
ent/470/contributions/2657/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2657/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The QCD deconfinement critical point as a function of N_t with N_f
=2 flavours of unimproved Wilson fermions
DTSTART;VALUE=DATE-TIME:20160725T154500Z
DTEND;VALUE=DATE-TIME:20160725T160500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2611@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Christopher Czaban (Goethe University Frankfurt am M
ain)\nQCD at zero baryon density in the limit of infinite quark mass under
goes a first order deconfinement phase transition at a critical temperatur
e T_c corresponding to the breaking of the global centre symmetry.\nIn the
presence of dynamical quarks the global centre symmetry is explicitly bro
ken. Lowering the quark mass the first order phase transition weakens and
terminates in a second order Z(2) point. Beyond this line confined and dec
onfined regions are analytically connected by a crossover transition. \nAs
the continuum limit is approached (i.e. the lattice spacing is decreased)
the region of first order transitions expands towards lower masses. We st
udy the deconfinement critical point with standard Wilson fermions and N_f
=2 flavours. Therefore we simulate several kappa values on N_t=8 and vario
us aspect ratios in order to extrapolate to the thermodynamic limit\, appl
ying finite size scaling. We estimate if and when a continuuum extrapolati
on is possible.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributio
ns/2611/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2611/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Determination of latent heat at the finite temperature phase trans
ition of SU(3) gauge theory
DTSTART;VALUE=DATE-TIME:20160729T155000Z
DTEND;VALUE=DATE-TIME:20160729T161000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2610@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Shinji Ejiri (Niigata University)\nWe calculate the
energy gap (latent heat) and pressure gap between \nthe hot and cold phase
s of the SU(3) gauge theory at the first \norder deconfining phase transit
ion point. \nWe perform simulations around the phase transition point with
\nthe lattice size in the temporal direction Nt=6\, 8 and 12 and \nextrap
olate the results to the continuum limit. \nThe energy density and pressur
e are evaluated by the derivative \nmethod with non-perturabative anisotro
py coefficients and by a \nmethod using the Yang-Mills gradient flow. \nWe
find that the pressure gap vanishes at all values of Nt when \nthe deriva
tive method is used. \nThe spatial volume dependence in the latent heat is
found to be \nsmall on large lattices. \nPerforming extrapolation to the
continuum limit\, we obtain \n$\\Delta \\epsilon/T^4 = 0.75 \\pm 0.17$ \na
nd \n$\\Delta (\\epsilon -3 p)/T^4 = 0.623 \\pm 0.056.$\n\nhttps://confere
nce.ippp.dur.ac.uk/event/470/contributions/2610/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2610/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Roberge-Weiss endpoint in $N_f=2+1$ QCD at the physical point
DTSTART;VALUE=DATE-TIME:20160725T170500Z
DTEND;VALUE=DATE-TIME:20160725T172500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2608@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Michele Mesiti (University of Pisa and INFN - Sezion
e di Pisa)\nIn this talk I will report on our recent results about the
\ndetermination of the position and the nature
of the Roberge-Weiss \nendpoint. Our study is per
formed in $N_f=2+1$ QCD\, with physical quark \nmasses\
, making use of stout-improved staggered fermions and of the
\ntree level Symanzik improvement for the gauge action. We study
the \ntheory at 4 different lattice spacings\, cor
responding to $N_t=4\,6\,8$ \nand $10$\, and at diffe
rent spatial sizes. The finite size scaling analysis\nperformed on $N_t=4$
and $6$ lattices indicates that the Roberge-Weiss\ntransition at the endp
oint is of the 2nd order kind\, in the 3D Ising\nuniversality class\, whil
e the continuum limit of the critical\ntemperature is found to be $T_{RW}=
208(5)$ MeV.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/
2608/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2608/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Relative weights approach to dynamical fermions at finite densitie
s
DTSTART;VALUE=DATE-TIME:20160728T171000Z
DTEND;VALUE=DATE-TIME:20160728T173000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2606@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jeffrey Greensite (San Francisco State University)\n
The relative weights method is applied to extract the effective Polyakov l
ine action corresponding to SU(3) gauge theory with dynamical staggered fe
rmions\, and this theory is solved\, at finite chemical potential and a fe
w sample temperatures\, quark masses\, and couplings\, by a mean field tec
hnique. The effective Polyakov line action is highly non-local\, and in a
t least one case we encounter very long-lived metastable states in the num
erical simulation.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contribu
tions/2606/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2606/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Viscosity of the pure SU(3) gauge theory revisited
DTSTART;VALUE=DATE-TIME:20160729T171000Z
DTEND;VALUE=DATE-TIME:20160729T173000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2599@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Attila Pasztor (University of Wuppertal\, for the Wu
ppertal-Budapest collaboration)\nWe give a preliminary estimate of the she
ar viscosity and the sound attenuation length in a pure SU(3) gluon plasma
\, using an improved anisotropic gauge action. We use Wilson-flow for anis
otropy tuning\, shifted boundary conditions for renormalization\, and a mu
ltilevel algorithm\nfor the measurement of the energy-momentum tensor corr
elators. We also look at the continuum limit of the momenta of the spectra
l function by using $N_t=10\,12\,16$ lattices.\n\nhttps://conference.ippp.
dur.ac.uk/event/470/contributions/2599/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2599/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics with physical mass staggered quarks
DTSTART;VALUE=DATE-TIME:20160725T131500Z
DTEND;VALUE=DATE-TIME:20160725T133500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2577@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Kalman Szabo (U Wuppertal\, FZ Juelich)\nFinite temp
erature lattice QCD is investigated with four flavor physical mass stagger
ed quarks using lattices upto N_t=20. Results for the equation of state an
d the low-lying modes of the Dirac-operator are presented with a focus on
lattice artefacts.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contribu
tions/2577/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2577/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Axion Phenomenology from Unquenched Lattice QCD
DTSTART;VALUE=DATE-TIME:20160729T130000Z
DTEND;VALUE=DATE-TIME:20160729T132000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2575@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Guido Martinelli (Universita' di Roma "La Sapienza"
and Cern)\nWe investigate the topological properties of $N_f = 2 + 1$ QCD
with\nphysical quark masses\, both at zero and finite temperature. At zero
\ntemperature both finite size and finite cut-off effects have been\nstud
ied by comparing the continuum extrapolated results for the\ntopologica
l susceptibility $\\chi$ with the predictions from chiral\nperturbation th
eory. At finite temperature\, we explore a region going\nfrom $T_c$ up to
around $4T_c$\, where continuum extrapolated results for the\ntopological
susceptibility and for the fourth moment of the topological\ncharge distr
ibution are obtained. While the fourth moment converges to\nthe dilute in
stanton gas prediction the topological susceptibility\ndiffers strongly b
oth in the size and in the temperature dependence.\nThis results in a shif
t of the axion dark matter window of almost one\norder of magnitude with r
espect to the instanton computation.\n\nhttps://conference.ippp.dur.ac.uk/
event/470/contributions/2575/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2575/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Nuclear and Chiral Transition in the Strong Coupling Regime of
Lattice QCD
DTSTART;VALUE=DATE-TIME:20160729T153000Z
DTEND;VALUE=DATE-TIME:20160729T155000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2573@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Wolfgang Unger (Bielefeld University)\nLattice QCD i
n the strong coupling limit with staggered quarks gives rise to a dual rep
resentation. Here\, the sign problem is mild enough to study the phase dia
gram at finite density. In the strong coupling limit\, the first order nuc
lear and chiral transition at low temperatures coincide due to Pauli satur
ation. \n\nAway from the strong coupling limit\, incorporating higher orde
r gauge corrections\, both transitions are expected to split\, with an int
ermediate phase of nuclear matter where chiral symmetry is still broken. \
n \nWe show numerical evidence from Monte Carlo simulations in the dual re
presentation that indicate this splitting.\n\nhttps://conference.ippp.dur.
ac.uk/event/470/contributions/2573/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2573/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Parity doubling in two-color and two-flavor gauge theory at high t
emperature
DTSTART;VALUE=DATE-TIME:20160729T134000Z
DTEND;VALUE=DATE-TIME:20160729T140000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2568@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jong-Wan Lee (Swansea University)\nRecently the two-
color gauge theory with two flavors of fundamental fermions has received c
onsiderable attention in BSM model building\, as it provides a minimal tem
plate for a composite Higgs theory that includes dark matter candidates. I
n this work\, we consider the two-color model with two flavors of Wilson f
ermions at non-zero temperature. For a more reliable investigation of meso
n correlation functions at high temperature\, we perform simulations on an
isotropic lattices with a target anisotropic factor of a_s/a_t=6.3. The tu
ning of bare parameters was carried out using the pseudo-scalar dispersion
relation and Wilson loop ratios. We present our preliminary results for t
he identification of parity doubling from the temporal and spacial correla
tion functions of vector and axial-vector mesons.\n\nhttps://conference.ip
pp.dur.ac.uk/event/470/contributions/2568/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2568/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Continuum limit and universality of the Columbia plot
DTSTART;VALUE=DATE-TIME:20160725T141500Z
DTEND;VALUE=DATE-TIME:20160725T143500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2567@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Philippe de Forcrand (ETH Zurich &\; CERN)\nIn it
s lower left corner\, the Columbia plot indicates a first-order\nfinite-te
mperature phase transition\, which turns into a crossover\nas the quark ma
sses increase. The locus of quark masses giving a\nsecond-order transition
is a feature of continuum QCD\, and should\nbe recovered with any fermion
discretization. However\, numerical\nevidence has been accumulating\, dis
favoring universality.\nWe explore this puzzle with 4 degenerate flavors o
f staggered\nfermions\, thus avoiding any potential problem associated wit
h rooting.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/25
67/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2567/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Open charm correlators and spectral functions at high temperature
DTSTART;VALUE=DATE-TIME:20160728T130000Z
DTEND;VALUE=DATE-TIME:20160728T132000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2566@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jon-Ivar Skullerud (Maynooth University)\nWe present
results for correlators and spectral functions of open charm mesons using
2+1 flavours of clover fermions on anisotropic lattices. The D mesons ar
e found to melt close to the deconfinement crossover temperature $T_c$. O
ur preliminary results suggest a shift in the thermal D meson mass below $
T_c$.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2566/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2566/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The QCD equation of state at finite density from analytical contin
uation
DTSTART;VALUE=DATE-TIME:20160727T105000Z
DTEND;VALUE=DATE-TIME:20160727T111000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2559@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jana Günther (University of Wuppertal)\nAn efficien
t way to study the QCD phase diagram at small finite density is to extrapo
late thermodynamical observables from imaginary chemical potential. In thi
s talk we present results on several observables for the equation of state
to order (muB/T)^6. The observables are calculated along the isentropic t
rajectories in the (T\, muB ) plane corresponding to the RHIC Beam Energy
Scan collision energies. The simulations are performed at the physical mas
s for the light and strange quarks. muS was tuned in a way to enforce stra
ngeness neutrality to match the experimental conditions\; the results are
continuum extrapolated using lattices of up to Nt = 16 temporal resolution
.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2559/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2559/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Talk withdrawn
DTSTART;VALUE=DATE-TIME:20160727T084000Z
DTEND;VALUE=DATE-TIME:20160727T090000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2558@conference.ippp.dur.ac.uk
DESCRIPTION:https://conference.ippp.dur.ac.uk/event/470/contributions/2558
/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2558/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Reweighting trajectories from the complex Langevin method
DTSTART;VALUE=DATE-TIME:20160726T171000Z
DTEND;VALUE=DATE-TIME:20160726T173000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2549@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jacques Bloch (University of Regensburg)\nWe introdu
ce the reweighted complex Langevin method\, which enlarges the applicabili
ty range of the complex Langevin method by reweighting the complex traject
ories. In this reweighting procedure both the auxiliary and target ensembl
es have a complex action. We validate the method by applying it to a rando
m matrix model for QCD and to two-dimensional strong-coupling QCD\, both a
t nonzero chemical potential\, and observe that it gives access to mass re
gions that could otherwise not be reached with the complex Langevin method
.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2549/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2549/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stochastic approaches to extract spectral functions from Euclidean
correlators
DTSTART;VALUE=DATE-TIME:20160728T134000Z
DTEND;VALUE=DATE-TIME:20160728T140000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2546@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Haitao Shu (CCNU)\nThe spectral functions provide us
the knowledge to understand the in-medium hadron and transport properties
of the QCD medium. For instance\, quantities like thermal dilepton produc
tion and photon emission rates of QGP can be obtained from the vector spec
tral functions. Though spectral functions are important\, they can not be
obtained directly from Euclidean lattice QCD calculations. Analytic contin
uations to real time are needed to extract spectral functions from Euclide
an correlation functions. Currently the most commonly used method is the M
aximum Entropy Method (MEM). To investigate the systematic uncertainties i
n spectral function reconstructions we study two stochastic approaches\, i
.e. Stochastic Optimization Method (SOM) and Stochastic Analytical Inferen
ce (SAI). SOM has advantage that it does not need any prior information. S
AI is more generalized method\, which reduces to the MEM in the mean-field
limit. We compare results obtained from these two methods with those from
MEM by investigating various model correlation functions.\n\nhttps://conf
erence.ippp.dur.ac.uk/event/470/contributions/2546/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2546/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On complex Langevin dynamics and zeroes of the determinant
DTSTART;VALUE=DATE-TIME:20160726T155000Z
DTEND;VALUE=DATE-TIME:20160726T161000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2542@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Gert Aarts (Swansea University)\nIn the complex Lang
evin approach to lattice simulations at nonzero density\, zeroes of the fe
rmion determinant lead to a meromorphic drift and hence a need to revisit
the theoretical justification. In this talk we discuss how poles in the dr
ift affect the formal justification of the approach and then explore the v
arious possibilities in simple models. The implications of the findings fo
r heavy dense QCD and full QCD are discussed.\n\nhttps://conference.ippp.d
ur.ac.uk/event/470/contributions/2542/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2542/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quark Mass Dependence of the QCD Critical End Point in the Strong
Coupling Limit
DTSTART;VALUE=DATE-TIME:20160729T155000Z
DTEND;VALUE=DATE-TIME:20160729T161000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2541@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Jangho KIM (Fakultät für Physik\, Universität Bie
lefeld)\nStrong coupling lattice QCD in the dual representation allows to
study the full mu-T phase diagram\, due to the mildness of the sign proble
m. This has been done in the chiral limit. Here we extend the phase diagra
m to finite quark masses. We present our results on the quark mass depende
nce of the QCD critical end point obtained by Monte Carlo via the worm alg
orithm. We compare our simulations which are performed on 4^3x4\, 6^3x4\,
8^3x4\, 12^3x4\, 16^3x4 lattices with mean field results.\n\nhttps://confe
rence.ippp.dur.ac.uk/event/470/contributions/2541/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2541/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Spontaneous symmetry breaking induced by complex fermion determina
nt --- yet another success of the complex Langevin method
DTSTART;VALUE=DATE-TIME:20160726T144000Z
DTEND;VALUE=DATE-TIME:20160726T150000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2532@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Yuta Ito (KEK)\nIn many interesting systems\, the fe
rmion determinant becomes complex and its phase plays a crucial role in th
e determination of the vacuum. For instance\, in finite density QCD at low
temperature and high density\, exotic fermion condensates are conjectured
to form due to such effects. When one applies the complex Langevin method
to such a complex action system naively\, one cannot obtain the correct r
esults because of the singular-drift problem associated with the appearanc
e of small eigenvalues of the Dirac operator. Here we propose to add a fer
mion bilinear term to the action to avoid this problem and extrapolate its
coefficient to zero. We test this idea in an SO(4)-invariant matrix model
with a Gaussian action and a complex fermion determinant\, whose phase is
expected to induce the spontaneous breaking of the SO(4) symmetry. Our re
sults agree well with the previous results obtained by the Gaussian expans
ion method.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2
532/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2532/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Temperature dependence of topological susceptibility using gradien
t flow
DTSTART;VALUE=DATE-TIME:20160729T161000Z
DTEND;VALUE=DATE-TIME:20160729T163000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2530@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Yusuke Taniguchi (University of Tsukuba)\nTopologica
l susceptibility brings important information of the QCD vacuum and\ncontr
ibutes to a production of the axion. The temperature dependence of the top
ological susceptibility plays a crucial role in its production rate in the
early universe.\nIt is a test whether the axion can be an appropriate can
didate of the dark matter.\nIn this talk we report our recent study on the
topological susceptibility in the finite temperature QCD with Nf=2+1 flav
ors.\nThe topological susceptibility is given by applying the gradient flo
w to the finite temperature system. We cover a wide range of temperature r
egion $174\\le T\\le697$ MeV.\nThe ud quark mass is rather heavy $m_\\pi/m
_\\rho=0.63$ and s quark mass is\nset to almost the physical value.\n\nhtt
ps://conference.ippp.dur.ac.uk/event/470/contributions/2530/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2530/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Equation of state in (2+1)-flavor QCD with gradient flow
DTSTART;VALUE=DATE-TIME:20160727T103000Z
DTEND;VALUE=DATE-TIME:20160727T105000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2524@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Kazuyuki Kanaya (CiRfSE\, Univ. Tsukuba)\nThe energy
-momentum tensor and the equation of state are studied in finite-temperatu
re (2+1)-flavor QCD with improved Wilson quarks\, using the gradient flow
method proposed by Makino and Suzuki. Although the up and down quarks are
heavy yet ($m_{\\rm PS}/m_V \\approx 0.63$)\, we obtain reasonable results
\, suggesting that the method works well. We also report on the results on
the chiral condensate and its susceptibility with the gradient flow metho
d.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2524/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2524/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sign problem in heavy-dense QCD from a density-of-states perspecti
ve
DTSTART;VALUE=DATE-TIME:20160726T134000Z
DTEND;VALUE=DATE-TIME:20160726T140000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2523@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Nicolas Garron (PU)\nWe investigate QCD at finite de
nsities of heavy quarks from a density-of-state perspective. Using the LLR
approach\, we can compute the phase-factor expectation value in the stron
g sign problem regime with unprecedented precision due to its inherent exp
onential error suppression. \nWe use our findings to draw conclusions on
the approach using phase cumulants.\n\nhttps://conference.ippp.dur.ac.uk/e
vent/470/contributions/2523/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2523/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Critical endline of the finite temperature phase transition for 2+
1 flavor QCD around the SU(3)-flavor symmetric point
DTSTART;VALUE=DATE-TIME:20160725T143500Z
DTEND;VALUE=DATE-TIME:20160725T145500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2507@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Yoshifumi Nakamura (RIKEN)\nWe investigate the criti
cal endline of the finite temperature phase transition of QCD around the
SU(3)-flavor symmetric point at zero chemical potential.\nWe employ the re
normalization-group improved Iwasaki gauge action and non-perturbatively $
O(a)$-improved Wilson-clover fermion action.\nThe critical endline is det
ermined by using the intersection point of kurtosis\, employing the multi-
parameter\, multi-ensemble reweighting method to calculate observables off
the SU(3)-symmetric point\, at the temporal size $N_{\\rm T}$=6 and latt
ice spacing as low as $a \\approx 0.19$ fm.\nWe confirm that the slope of
the critical endline takes the value of $-2$\, and find that the second
derivative is positive\, at the SU(3)-flavor symmetric point on the Columb
ia plot parametrized with the strange quark mass $m_s$ and degenerated up-
down quark mass $m_{\\rm l}$.\n\nhttps://conference.ippp.dur.ac.uk/event/4
70/contributions/2507/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2507/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Phase diagram of the O(3) model from dual lattice simulations
DTSTART;VALUE=DATE-TIME:20160727T111000Z
DTEND;VALUE=DATE-TIME:20160727T113000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2502@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Falk Bruckmann (University of Regensburg)\nWe simula
ted the asymptotically free two-dimensional O(3) model at nonzero chemical
potential through dual variables free of the sign problem. The system und
ergoes a quantum phase transition when mu reaches the particle mass (gener
ated dynamically similar to QCD). The density follows a square root univer
sal for repulsive bosons in one spatial dimension. We have also measured t
he spin stiffness\, known to be sensitive to the spatial correlation lengt
h\, in different scaling trajectories to zero temperature and infinite siz
e. It points to a dynamical critical exponent z=2\, which can be explained
by particle worldlines. Comparisons to thermodynamic Bethe ansaetze are s
hown as well.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions
/2502/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2502/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics of strongly interacting plasma with high accuracy
DTSTART;VALUE=DATE-TIME:20160729T153000Z
DTEND;VALUE=DATE-TIME:20160729T155000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2496@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Michele Pepe (INFN - Sez. Milano Bicocca - Italy)\nT
he thermodynamic properties of the $SU(3)$ Yang-Mills theory are\ninvestig
ated from the confining phase up to 250 $T_c$. Results for the\ntemperatur
e dependence of the entropy density\, energy density and pressure\nare pre
sented with an accuracy of about 0.5%. The framework of shifted\nboundary
conditions is considered where the entropy density is related to\nthe expe
ctation value of the off-diagonal components of the\nenergy-momentum tenso
r. The pressure and the energy density are then\nobtained by numerical int
egration. A comparison with data collected by\nother groups is discussed.\
n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2496/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2496/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Study of the sign problem in canonical approach
DTSTART;VALUE=DATE-TIME:20160727T094000Z
DTEND;VALUE=DATE-TIME:20160727T100000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2489@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Asobu Suzuki (University of Tsukuba)\nCanonical appr
oach is one of the powerful tools to approach the QCD phase diagram. We ca
lculate the canonical partition function instead of the grand canonical on
e in the canonical approach. However\, it is known that the sign problem e
merges as a complex phase of the canonical partition function.\n Thanks to
multi-precision calculations with the canonical approach we obtained the
canonical partition function even for large baryon numbers. In this talk\,
we will argue the origin of this "phase"\, and study some behavior of its
temperature and baryon number dependence.\n\nhttps://conference.ippp.dur.
ac.uk/event/470/contributions/2489/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2489/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On the condition for correct convergence in the complex Langevin m
ethod
DTSTART;VALUE=DATE-TIME:20160726T163000Z
DTEND;VALUE=DATE-TIME:20160726T165000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2482@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Shinji Shimasaki (Keio University)\nThe complex Lang
evin method (CLM) is a promising way to perform the path integral with a c
omplex action based on a stochastic equation for complexified dynamical va
riables. It is known\, however\, that the CLM gives wrong results in some
cases\, while it works\, for instance\, in finite density QCD in the decon
finement phase or in the heavy dense limit. In this talk\, we revisit this
issue starting with a finite Langevin step-size. We find that there is a
subtlety in taking the zero step-size limit\, although the previous argume
nt used a continuous time from the beginning. Also there is a subtlety in
using the time-evolved observables\, which play a crucial role in the argu
ment. These subtleties require that the probability distribution of the dr
ift term should be suppressed exponentially at large magnitude. We demonst
rate our claim in some examples including chiral Random Matrix Theory and
show that our criterion is indeed useful in judging whether the results ob
tained by the CLM are trustable or not.\n\nhttps://conference.ippp.dur.ac.
uk/event/470/contributions/2482/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2482/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Static and non-static vector screening masses
DTSTART;VALUE=DATE-TIME:20160728T144000Z
DTEND;VALUE=DATE-TIME:20160728T150000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2476@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Aman Steinberg (Uni Mainz)\nThermal screening masses
associated to the conserved vector current are calculated both in a weak-
coupling and a lattice QCD approach. The inverse of a screening mass can b
e understood as the length scale over which an external electric field is
screened in a QCD medium. The comparison of screening masses in the zero a
nd non-zero Matsubara frequency sectors shows good agreement of the pertur
bative and the lattice results. Moreover\, at *T* ≈ 508MeV the lightest
screening mass lies above the free result $(2n\\pi T)$\, in agreement with
the $\\mathcal{O}(g^2)$ weak-coupling prediction\, whereas this was not t
he case in a previous study at *T* ≈ 254MeV.\n\nhttps://conference.ippp.
dur.ac.uk/event/470/contributions/2476/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2476/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Parity doubling of nucleons and Delta baryons across the deconfine
ment phase transition
DTSTART;VALUE=DATE-TIME:20160729T132000Z
DTEND;VALUE=DATE-TIME:20160729T134000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2473@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Davide De Boni (Swansea University)\nAt zero tempera
ture nucleons and their parity partners have non-degenerate\nmasses due to
spontaneous breaking of chiral symmetry.\nHowever\, chiral symmetry is ex
pected to be restored at sufficiently high temperature\,\nin particular wh
en going from the hadronic to the quark-gluon plasma (QGP) phase\,\nimplyi
ng that the parity partners should become degenerate.\nWe study the nucleo
n (spin 1/2) and Delta (spin 3/2) baryons in both\nparity sectors for a ra
nge of temperatures in the confined and QGP phases.\nUsing anisotropic $N_
f = 2+1$ flavour simulations\, we analyse the correlation functions and th
e spectral functions\nusing respectively exponential fits and the Maximum
Entropy Method.\nWe find a clear sign of parity doubling for both baryons
in the QGP phase:\nthe parity state masses become degenerate and\ntheir co
rresponding correlators become essentially identical.\n\nhttps://conferenc
e.ippp.dur.ac.uk/event/470/contributions/2473/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2473/
END:VEVENT
BEGIN:VEVENT
SUMMARY:QCD with isospin chemical potential: pion condensation
DTSTART;VALUE=DATE-TIME:20160728T153000Z
DTEND;VALUE=DATE-TIME:20160728T155000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2471@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Gergely Endrodi (University of Frankfurt)\nWe study
the QCD phase diagram at nonzero isospin chemical potential\nusing 2+1 fla
vors of staggered fermions with physical quark masses at\ndifferent lattic
e spacings and volumes. The talk focuses on the\ntransition to the pion co
ndensation phase at high chemical potentials.\nThis phase is characterized
by a proliferation of low modes that slow\ndown the simulation considerab
ly and necessitate the use of an\ninfrared regulator. We discuss a novel s
trategy to determine the pion\ncondensate in the limit of vanishing regula
tors.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2471/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2471/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Comparison of CLE and reweighting for QCD at nonzero density
DTSTART;VALUE=DATE-TIME:20160726T161000Z
DTEND;VALUE=DATE-TIME:20160726T163000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2465@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Denes Sexty (Uni Wuppertal)\nLattice QCD at non-vani
shing chemical potential is studied using the complex Langevin equation (C
LE). We compare the results with multi-parameter reweighting both from μ=
0 and phase quenched ensembles. A good agreement is found for lattice spac
ings below ≈0.15 fm. On coarser lattices the complex Langevin approach b
reaks down. Four flavors of staggered fermions are used on Nt=4\,6 and 8 l
attices. We also discuss the issue of poles for CLE simulations of HDQCD a
nd full QCD.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/
2465/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2465/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Using Wilson flow to study the deconfinement transition
DTSTART;VALUE=DATE-TIME:20160729T163000Z
DTEND;VALUE=DATE-TIME:20160729T165000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2456@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Saumen Datta (Tata Institute of Fundamental Research
)\nWe use the Wilson flow to study the deconfinement transition. We constr
uct \nrenormalized observables sensitive to the deconfinement transition.
In \nparticular\, behavior of renormalized operators associated with the P
olyakov \nloop are investigated for both quenched and two-flavor QCD. We a
lso \ninvestigate the behavior of various thermodynamic quantities across
the transition.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributio
ns/2456/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2456/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stochastic reconstruction of charmonium spectral functions at fini
te temperature
DTSTART;VALUE=DATE-TIME:20160728T140000Z
DTEND;VALUE=DATE-TIME:20160728T142000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2452@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Hiroshi Ohno (University of Tsukuba)\nWe study charm
onium spectral functions at finite temperature by using stochastic reconst
ruction methods. Our quenched lattice QCD simulations are performed with t
he standard plaquette gauge and the $O(a)$-improved Wilson fermion actions
on 192$^3 \\times N_\\tau$ lattices with $N_\\tau$ = 96--32\, which corre
sponds to temperatures from 0.73$T_c$ to 2.2$T_c$. To reconstruct the char
monium spectral functions for the Euclidean time correlators we apply two
different stochastic methods called Stochastic Analytical Inference (SAI)
and Stochastic Optimization Method (SOM)\, where the former is based on th
e Bayes' theorem similar to commonly used Maximum Entropy Method (MEM) whi
le the latter does not rely on any prior information. We carefully estimat
e systematic uncertainties by comparing results among SAI\, SOM and also M
EM. With the given spectral functions we discuss melting temperatures of c
harmonia as well as the heavy quark diffusion coefficient.\n\nhttps://conf
erence.ippp.dur.ac.uk/event/470/contributions/2452/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2452/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermalisation properties of various field theories
DTSTART;VALUE=DATE-TIME:20160729T171000Z
DTEND;VALUE=DATE-TIME:20160729T173000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2441@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Marietta Magdolna Homor (Eotvos Lorand University)\n
Motivated by the hadronization properties of heavy-ion and p-p collisions\
,\nwe study the thermalisation properties of field theories.\nFirst of all
\, we present our recent observations regarding the local energy-density\n
and momentum distributions in the classical Phi^4 theory.\nAs this theory
exhibits interesting features regarding these questions\,\nwe continue the
research by the MC simulation of the SU(3) Yang-Mills theory\nand we inte
nd to investigate further in more complicated theories.\n\nhttps://confere
nce.ippp.dur.ac.uk/event/470/contributions/2441/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2441/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roberge-Weiss periodicity and confinement-deconfinement transition
DTSTART;VALUE=DATE-TIME:20160725T164500Z
DTEND;VALUE=DATE-TIME:20160725T170500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2434@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Kouji Kashiwa (Yukawa Institute for Theoretical Phys
ics\, Kyoto University)\nWe propose a new determination of the confinement
-deconfinement transition by using the imaginary chemical potential. The i
maginary chemical potential can be interpreted as the Aharonov-Bohm phase
and then an analogy of the topological-order suggests that the Roberge-Wei
ss endpoint would define the deconfinement temperature. Based on the topol
ogical property\, we can construct a new quantity which describes the conf
inement-deconfinement transition. This quantity is defined as the integral
of the quark number susceptibility along the closed loop of $\\theta$ whe
re $\\theta$ is the dimensionless imaginary chemical potential. Expected b
ehavior of it at finite temperature is discussed and its asymptotic behavi
ors are shown.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contribution
s/2434/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2434/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Complex Langevin for Lattice QCD at $T=0$ and $\\mu \\ge 0$.
DTSTART;VALUE=DATE-TIME:20160726T153000Z
DTEND;VALUE=DATE-TIME:20160726T155000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2433@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Donald SInclair (Argonne-Seville)\nWe simulate Latti
ce QCD with 2 light quark flavours at zero temperature and finite quark nu
mber chemical potential $\\mu$. Gauge cooling is applied\, along with adap
tive rescaling of the updating `time' increment\, to stabilize the algorit
hm. We see evidence for the expected transition at $\\mu \\approx m_N/3$ a
nd for saturation at large $\\mu$. Limitations of the method are discussed
.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2433/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2433/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A gauge invariant Debye mass for the complex heavy-quark potential
DTSTART;VALUE=DATE-TIME:20160728T142000Z
DTEND;VALUE=DATE-TIME:20160728T144000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2431@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Alexander Rothkopf (Institute for Theoretical Physic
s\, Heidelberg University)\nThe concept of a screening mass is a powerful
tool to simplify the intricate physics of in-medium test charges surrounde
d by light charge carriers. While it has been successfully used to describ
e electromagnetic properties\, its definition and computation in QCD is pl
agued by questions of gauge invariance and the presence of non-perturbativ
e contributions from the magnetic sector.\n\nHere we present a recent alte
rnative definition [1] of a gauge invariant Debye mass parameter following
closely the original idea of Debye and Hueckel. Our test charges are a st
atic heavy quark-antiquark pair whose complex potential and its in-medium
modification can be extracted using lattice QCD [2]. By combining in a gen
eralized Gauss-Law the non-perturbative aspects of quark binding with a pe
rturbative ansatz for the medium effects\, we succeed to describe the latt
ice values of Re[V] and Im[V] [3] with a single temperature dependent para
meter\, in turn identified with a Debye mass. \n\nWe find that its behavio
r evaluated both in quenched QCD [4]\, as well as dynamical Nf=2+1 QCD [3]
deviates from that in other approaches\, such as hard-thermal-loop pertur
bation theory or from electric field correlators on the lattice. Around th
e phase transition e.g. its values tend to zero significantly faster than
at weak-coupling.\n\n[1] Y. Burnier\, A.R. Phys.Lett. B753 (2016) 232-236\
n[2] A.R.\, T. Hatsuda\, S. Sasaki\, Phys.Rev.Lett. 108 (2012) 162001\n[3]
Y.Burnier\, O. Kaczmarek\, A.R. Phys.Rev.Lett. 114 (2015) 082001\n[4] Y.B
urnier\, A.R. in preparation\n\nhttps://conference.ippp.dur.ac.uk/event/47
0/contributions/2431/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2431/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simulating thimble regularization of lattice quantum field theorie
s (including LGT)
DTSTART;VALUE=DATE-TIME:20160727T090000Z
DTEND;VALUE=DATE-TIME:20160727T092000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2423@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Francesco Di Renzo (University of Parma &\; INFN)
\nMonte Carlo simulations of lattice quantum field theories on Lefschetz t
himbles are non trivial. We discuss a new Monte Carlo algorithm based on t
he idea of computing contributions to the functional integral which come f
rom complete flow lines. The latter are the steepest ascent paths attached
to critical points\, i.e. the basic building blocks of thimbles. The meas
ure to sample is thus dictated by the contribution of complete flow lines
to the partition function. The algorithm is based on a heat bath sampling
of the gaussian approximation of the thimble: this defines the proposals f
or a Metropolis-like accept/reject step. The effectiveness of the algorith
m has been tested on a few models\, e.g. the chiral random matrix model. W
e also discuss thimble regularization of gauge theories\, and in particula
r the successfull application to 0+1 dimensional QCD and the status and pr
ospects for Yang-Mills theories.\n\nhttps://conference.ippp.dur.ac.uk/even
t/470/contributions/2423/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2423/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Landau Levels in Lattice QCD
DTSTART;VALUE=DATE-TIME:20160729T165000Z
DTEND;VALUE=DATE-TIME:20160729T171000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2420@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Ferenc Pittler (Eötvös University)\nThe spectrum o
f the two-dimensional continuum Dirac operator in\nthe presence of a unifo
rm background magnetic field consists of Landau\nlevels\, which are degene
rate and separated by gaps. On the lattice the\nLandau levels are spread o
ut by discretization artefacts\, but a\nremnant of their structure is clea
rly visible (Hofstadter butterfly).\nIf one switches on a non-Abelian inte
raction\, the butterfly structure\nwill be smeared out\, but the lowest La
ndau level will still be\nseparated by a gap from the rest of the spectrum
. In this talk we\ndiscuss how the eigenmodes of the four-dimensional QCD
Dirac operator\nare built out of the two-dimensional eigenmodes of the Dir
ac operator\ndiagonalized on each slice at fixed (z\,t). In particular\, s
tarting\nfrom this decomposition\, we consider how well certain physical\n
quantities are approximated by using only the two-dimensional\neigenmodes
belonging to the lowest Landau level.\n\nhttps://conference.ippp.dur.ac.uk
/event/470/contributions/2420/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2420/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Two-colour QCD at finite density with two flavours of staggered qu
arks
DTSTART;VALUE=DATE-TIME:20160728T163000Z
DTEND;VALUE=DATE-TIME:20160728T165000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2419@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Lukas Holicki (Justus-Liebig-University Giessen)\nLa
ttice simulations of two-colour QCD can be performed at finite density wit
hout sign problem and by now have a long history already. The physics of t
he bosonic diquark baryons is believed to be fairly well understood and qu
alitatively resembles QCD at finite isospin density with pion condensation
. There is good guidance from effective field theory predictions and model
studies of the BEC-BCS crossover inside the condensed phase. We have revi
sited the question how well this can all be described with rooted staggere
d quarks. A potential problem thereby is the proximity of the bulk phase.
We therefore use an improved gauge action and lattice couplings that somew
hat larger than those of the early studies with N f =8 and 4 flavours.\nTh
is implies that we have to worry about additive renormalization in the chi
ral condensate before we can compare our results with the effective field
theory predictions. We also confirm that the Polyakov-loop does not appear
to respond to the finite density in the staggered formulation\, and we pe
rform some basic meson and diquark spectroscopy at finite density.\n\nhttp
s://conference.ippp.dur.ac.uk/event/470/contributions/2419/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2419/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The chiral phase transition from non-integer flavour numbers with
staggered fermions
DTSTART;VALUE=DATE-TIME:20160725T162500Z
DTEND;VALUE=DATE-TIME:20160725T164500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2415@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Francesca Cuteri (Goethe University - Frankfurt)\nTh
e attempt at clarifying the order of the thermal transition in the chiral
limit of QCD at zero chemical potential\, with two dynamical flavours of q
uarks\, by progressively decreasing the simulated pion mass has proven to
be inconclusive because of the increasing costs of the simulations as the
pion mass is lowered.\n\nAn alternative way to approach this question is t
o consider the path integral as a function of continuous Nf . If the tra
nsition is first order for Nf ≳ 3 \, a second order transition for Nf =
2 requires a tricritical point in between.\n\nThe simulation of non-integ
er numbers of fermion flavours is easily achievable within the staggered f
ermion discretization. First simulations at μ = 0 and Nf = 2.8\, 2.6\,
2.4\, 2.2 \, on coarse Nτ = 4 lattices\, show a continuous variation o
f the critical mass mapping out a critical line in the m − Nf plane.\n
\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2415/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2415/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Comparison of algorithms for solving the sign problem of the finit
e $\\mu$ O(3) model in 1+1 dimensions
DTSTART;VALUE=DATE-TIME:20160729T140000Z
DTEND;VALUE=DATE-TIME:20160729T142000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2412@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Csaba Torok (Eotvos University\, Budapest)\nWe study
the 1+1 dimensional nonlinear O(3) model at finite chemical potential usi
ng the complex Langevin algorithm and the worm algorithm. In the latter th
e sign problem is totally eliminated. We determine the range of parameters
\, where complex Langevin produces correct results and study whether takin
g the continuum limit allows the exploration of the full phase diagram of
the model.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/24
12/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2412/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Chiral transition\, eigenmode localisation and Anderson-like model
s
DTSTART;VALUE=DATE-TIME:20160729T140000Z
DTEND;VALUE=DATE-TIME:20160729T142000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2410@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Matteo Giordano (Eötvös University\, Budapest)\nI
discuss chiral symmetry restoration and eigenmode localisation in\nfinite-
temperature QCD by looking at the lattice Dirac operator as a\nrandom Hami
ltonian. I will argue that the features of QCD relevant to\nboth phenomena
are the presence of order in the Polyakov line\nconfiguration\, and the c
orrelations that this induces between spatial\nlinks across time slices. T
his ties the fate of chiral symmetry and of\nlocalisation of the lowest Di
rac eigenmodes to the confining\nproperties of the theory. I then show num
erical results obtained in a\nQCD-inspired Anderson-like toy model\, deriv
ed by radically simplifying\nthe QCD dynamics while keeping the important
features mentioned\nabove. The toy model reproduces all the important qual
itative aspects\nof chiral symmetry breaking and localisation in QCD\, thu
s supporting\nthe central role played by the confinement/deconfinement tra
nsition in\ntriggering both phenomena.\n\nhttps://conference.ippp.dur.ac.u
k/event/470/contributions/2410/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2410/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Strangeness at finite temperature
DTSTART;VALUE=DATE-TIME:20160725T135500Z
DTEND;VALUE=DATE-TIME:20160725T141500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2407@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Szabolcs Borsanyi (University of Wuppertal)\nWe give
a lattice-based description of QCD thermodynamics in the\nhadronic phase
from staggered simulations of up to $N_t=16$.\nUsing generalized quark num
ber susceptibilities\nwe obtain the free energy in various strangeness sec
tors and\ncompare it with the expectations from the hadron resonance gas\n
model. We use the findings to disambiguate between various\nspectrum table
s. Thus we constrain the abundance of strange\nmesons and baryons using fi
nite temperature data\n\nhttps://conference.ippp.dur.ac.uk/event/470/contr
ibutions/2407/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2407/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Charm quark diffusion coefficient from nonzero momentum Euclidean
correlator in temporal channel
DTSTART;VALUE=DATE-TIME:20160728T132000Z
DTEND;VALUE=DATE-TIME:20160728T134000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2406@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Atsuro Ikeda (Osaka University)\nWe study the charm
quark diffusion coefficient from nonzero momentum correlator in temporal c
hannel on the quenched lattice. Euclidean correlator in temporal channel w
ith zero momentum is constant as a function of the imaginary time because
of the charge conservation. However this quantity with finite momentum is
dependent on imaginary time and is more sensitive to the low energy struct
ure of the spectral function than those in the spatial channel. We make es
timates on the diffusion coefficient from this channel. We perform the num
erical simulation on the lattice and apply the discussion for 1.5 \n\nht
tps://conference.ippp.dur.ac.uk/event/470/contributions/2406/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2406/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Non-Local effective SU(2) Polyakov loop model from inverse Monte-C
arlo methods
DTSTART;VALUE=DATE-TIME:20160728T165000Z
DTEND;VALUE=DATE-TIME:20160728T171000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2400@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Bardiya Bahrampour (Justus-Liebig University Giessen
)\nThe strong coupling expansion of the lattice gauge action leads to a Po
lyakov loop model that effectively describes the gluodynamic at low temper
atures and together with the hopping expansion of\nthe fermion determinant
allows for insights into the QCD phase diagram at finite density and low
temperatures\, although the accessible pion masses are rather large.\nAt h
igh temperatures the strong coupling expansion breaks down and it is expec
ted that the interaction of Polyakov loops becomes non-local.\nTherefore w
e use inverse Monte-Carlo methods to map pure SU(2) gluodynamic to differe
nt non-local Polyakov models . We take into account Polyakov loops in high
er representations and gradually add interaction terms at larger distances
to investigate how well we can describe the full theory. Particularly we
are interested in the behaviour of those models when extrapolating the de
pendency of non-local terms and higher represenations\, especially in the
large volume limit. We try to find connections between the strength of the
coupling of the non-local terms (with respect to the interaction distanc
e) and the correlation length of the full theory at a given value of the g
auge coupling in order to compare our results to existing proposals for no
n-local effective actions.\n\nhttps://conference.ippp.dur.ac.uk/event/470/
contributions/2400/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2400/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The CP(2) Model at Nonzero Chemical Potential
DTSTART;VALUE=DATE-TIME:20160729T132000Z
DTEND;VALUE=DATE-TIME:20160729T134000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2395@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Wynne Evans (University of Bern)\nCP(N-1) quantum fi
eld theories in (1+1)-d share important features with (3+1)-d QCD\, such a
s asymptotic freedom\, a dynamically generated mass gap and topological se
ctors. In the low energy limit the (2+1)-d SU(3) spin system undergoes spo
ntaneous symmetry breaking and hence dimensional reduction to the (1+1)-d
CP(2) model. By performing Monte Carlo simulations of (2+1)-d SU(3) spin s
ystems at non-zero chemical potential we have gained access to the (1+1)-d
CP(2) model at non-zero chemical potential. The theory which underpins ou
r calculation will be reviewed and numerical results for the magnetisation
s and correlation functions as a function of the chemical potentials will
be discussed.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions
/2395/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2395/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Functional Fit Approach (FFA) for Density of States method: SU(3)
spin system and SU(3) gauge theory with static quarks
DTSTART;VALUE=DATE-TIME:20160726T140000Z
DTEND;VALUE=DATE-TIME:20160726T142000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2393@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Mario Giuliani (University of Graz)\nWe study new de
velopments for the Density of States (DoS) method to simulate systems\na
ﬀected by the complex action problem. In particular we use the functiona
l ﬁt approach\n(FFA). It consists of a restricted Monte Carlo simulation
with an additional Boltzmann \nfactor\, which allows one to explore the D
oS for a given part of the spectrum. We\nﬁt the simulation data with a k
nown function to obtain the parameters of the DoS.\nWe apply the approach
to two model systems: 1) The SU(3) spin system with a chemical potential\;
2) The SU3 gauge theory with static quarks. We discuss the technical chal
lenges \nand the potential of FFA DoS.\n\nhttps://conference.ippp.dur.ac.u
k/event/470/contributions/2393/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2393/
END:VEVENT
BEGIN:VEVENT
SUMMARY:QCD with isospin chemical potential: low densities and Taylor expa
nsion
DTSTART;VALUE=DATE-TIME:20160728T155000Z
DTEND;VALUE=DATE-TIME:20160728T161000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2392@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Bastian Brandt (University of Frankfurt)\nWe investi
gate the phase diagram of QCD at finite isospin chemical potential using 2
+1 flavours of staggered fermions with physical quark masses at different
lattice spacings and volumes. In this talk we focus on the region of small
isospin chemical potential below the phase boundary to the pion condensat
ion phase and investigate the change of the transition temperature with th
e chemical potential. To investigate the convergence properties and the ra
nge of validity of the Taylor expansion method at a given order\, we compa
re our results to the Taylor expansion for finite isospin chemical potenti
al at 4 derivative order. This can serve as an important crosscheck for th
e Taylor expansion method at finite baryon chemical potential\, where dire
ct simulations are impossible due to the sign problem.\n\nhttps://conferen
ce.ippp.dur.ac.uk/event/470/contributions/2392/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2392/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Complex Langevin Dynamics for a Random Matrix Model of QCD at fini
te density
DTSTART;VALUE=DATE-TIME:20160726T142000Z
DTEND;VALUE=DATE-TIME:20160726T144000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2373@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Savvas Zafeiropoulos (Goethe University Frankfurt)\n
We study a Random Matrix Model for QCD at finite density via Complex Lange
vin dynamics. This model has a phase transition to a phase with non-zero b
aryon density. We study the convergence of the algorithm as a function of
the quark mass and the chemical potential and focus on two main observable
s: the baryon density and the chiral condensate. As expected\, for simulat
ions close to the chiral limit\, the algorithm has wrong convergence prope
rties when the quark mass is in the spectral domain of the quenched Dirac
operator. Possible solutions of this problem are discussed.\n\nhttps://co
nference.ippp.dur.ac.uk/event/470/contributions/2373/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2373/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effective Polyakov Loop Models for QCD-like Theories at Finite Den
sity
DTSTART;VALUE=DATE-TIME:20160729T144000Z
DTEND;VALUE=DATE-TIME:20160729T150000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2359@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Philipp Scior (TU Darmstadt)\nWe study the heavy qua
rk limit of QCD-like theories by using a three-dimensional Polyakov theory
. This theory can be derived from the full QCD-like theory by a combined s
trong coupling and hopping expansion. In particular we investigate the col
d and dense regime of the phase diagram where we expect to find the Silver
blaze property realized as Bose-Einstein-condensation of diquarks or a fis
t order liquid-gas transition depending on the gauge group of the theory.
We find evidence for the Silverblaze property when the quark chemical pote
ntial $\\mu$ reaches half the diquark mass. For even higher $\\mu$ we find
a the rise of the Polyakov loop as well as the quark number density.\n\nh
ttps://conference.ippp.dur.ac.uk/event/470/contributions/2359/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2359/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simulating low dimensional QCD on Lefschetz thimbles
DTSTART;VALUE=DATE-TIME:20160727T080000Z
DTEND;VALUE=DATE-TIME:20160727T082000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2358@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Christian Schmidt (Universitaet Bielefeld)\nNon-pert
urbative lattice QCD calculations at non-vanishing baryon\nnumber density
are hampered by the sign problem. The path\nintegral becomes highly oscill
ating and standard Monte Carlo techniques\nseize working. One possible sol
ution is the Lefschetz thimble\napproach. It requires a deformation of the
original integration domain\ninto a manifold embedded in complex space. F
or properly chosen\nintegration manifolds (``thimbles'') the sign problem
is drastically\nalleviated. For some bosonic and fermionic models this app
roach has\nbeen shown to work. In this talk we will discuss aspects of the
\nthimble discretization of low dimensional QCD.\n\nhttps://conference.ipp
p.dur.ac.uk/event/470/contributions/2358/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2358/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics with continuum extrapolated overlap fermions
DTSTART;VALUE=DATE-TIME:20160725T133500Z
DTEND;VALUE=DATE-TIME:20160725T135500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2356@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Sandor Katz Katz (Eotvos University\, Budapest)\nWe
study the QCD transition with dynamical overlap fermions. A continuum extr
apolation is carried out using lattices up to N_t=12. We use a fixed topol
ogy approach and study its effect on our observables.\n\nhttps://conferenc
e.ippp.dur.ac.uk/event/470/contributions/2356/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2356/
END:VEVENT
BEGIN:VEVENT
SUMMARY:New results for QCD at non-vanishing chemical potentials from Tayl
or expansion
DTSTART;VALUE=DATE-TIME:20160725T145500Z
DTEND;VALUE=DATE-TIME:20160725T151500Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2341@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Edwin Laermann (Bielefeld University)\nWe present re
cent results for QCD at non-vanishing chemical potentials for baryon numbe
r\, electric charge and strangeness.\nThe results are obtained from Taylor
expanding the QCD partition function up to sixth order in these potential
s.\nThe numerical simulations for two light and one strange quark have bee
n carried out on the basis of the Highly Improved Staggered Quark (HISQ) d
iscretization scheme at lattice spacings which in the vicinity of the chir
al transition temperature correspond to temporal extents of Nt = 6\, 8 and
12\, and at mass values which correspond to a physical Kaon mass and pion
Goldstone masses around the physical value of 140 MeV.\nThe results on\,
for instance\, the equation of state are obtained as function of the three
different chemical potentials and can thus also easily be adjusted to exp
erimental conditions met in heavy ion colliders.\n\nhttps://conference.ipp
p.dur.ac.uk/event/470/contributions/2341/
LOCATION:Highfield Campus\, University of Southampton Building 32 Room 101
5
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2341/
END:VEVENT
BEGIN:VEVENT
SUMMARY:What we can learn from two-dimensional QCD-like theories at finite
density
DTSTART;VALUE=DATE-TIME:20160729T134000Z
DTEND;VALUE=DATE-TIME:20160729T140000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2340@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Bjoern Wellegehausen (ITP University Giessen)\nTheor
etical knowlegde about the nonperturbative aspects of the phase diagram of
QCD is of utmost \nimportance for the design of future collider experimen
ts or the understanding of cold and dense neutron stars.\n\nSince lattice
QCD suffers from a severe sign problem at finite density\, QCD-like theori
es are useful to understand the phase diagram\nof baryonic matter at finit
e density. Most QCD-like theories (two-color QCD\, $G_2$-QCD or adjoint QC
D) contain bosonic baryons\, for example diquarks\, or other more exotic t
ypes of matter.\nIt is important to understand the interactions of these p
articles with ordinary fermionic baryons present in QCD.\n\nSimulations of
these theories\, for instance $G_2$-QCD\, reveal an interesting and rich
phase diagram at zero temperature. Many open questions arise\, partly due
to the lack of high precision or large volume/continuum data. This is the
reason why we study two-dimensional QCD-like theories. In the talk we shal
l discuss\ndifferences between QCD-like theories at baryon chemical and is
ospin chemical potential. Furthermore we present simulation results on the
phase diagram and spectroscopy at finite density for $G_2$- and two-color
-QCD and compare it to free lattice fermions. Finally we give an outlook t
o our ongoing simulations in four dimensions.\n\nhttps://conference.ippp.d
ur.ac.uk/event/470/contributions/2340/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2340/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A worm algorithm for the lattice CP(N-1) model
DTSTART;VALUE=DATE-TIME:20160729T130000Z
DTEND;VALUE=DATE-TIME:20160729T132000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2327@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Tobias Rindlisbacher (ETH Zürich)\nThe CP(N-1) mode
l in 2D is an interesting toy model for 4D QCD as it possesses confinement
\, asymptotic freedom and a non-trivial vacuum structure. Due to the lower
dimensionality and the absence of fermions\, the computational cost for s
imulating 2D CP(N-1) on the lattice is much lower than the one for simulat
ing 4D QCD. However to our knowledge\, no efficient algorithm for simulati
ng the lattice CP(N-1) model has been tested so far\, which also works at
finite density. To this end we propose a new type of worm algorithm which
is appropriate to simulate the lattice CP(N-1) model in a dual\, flux-vari
ables based representation\, in which the introduction of a chemical poten
tial does not give rise to any complications.\n\nhttps://conference.ippp.d
ur.ac.uk/event/470/contributions/2327/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2327/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thermodynamics of strongly-coupled lattice QCD in the chiral limit
DTSTART;VALUE=DATE-TIME:20160729T161000Z
DTEND;VALUE=DATE-TIME:20160729T163000Z
DTSTAMP;VALUE=DATE-TIME:20200602T052044Z
UID:indico-contribution-500-2325@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Helvio Vairinhos (ETH Zurich)\nIn the strong couplin
g limit\, n-point functions in lattice QCD with staggered fermions can be
rewritten exactly as traces over constrained configurations of monomers\,
dimers\, and baryon loops covering the spacetime lattice. Worm algorithms
provide efficient global sampling methods over such ensembles\, and are pa
rticularly efficient in the chiral limit. We study the thermodynamics of s
trongly-coupled U(3) and SU(3) lattice QCD with one massless staggered fer
mion using such methods\, and compare the results with the relativistic pi
on gas.\n\nhttps://conference.ippp.dur.ac.uk/event/470/contributions/2325/
LOCATION:Highfield Campus\, University of Southampton Building 67 Room 102
7
URL:https://conference.ippp.dur.ac.uk/event/470/contributions/2325/
END:VEVENT
END:VCALENDAR