Conveners
QCD at non-zero temperature: TR5
- Anders Tranberg (University of Stavanger, Norway)
QCD at non-zero temperature: TR5
- Johann Ostmeyer (Bonn University)
QCD at non-zero temperature: LT2
- Alexei Bazavov (Michigan State University)
QCD at non-zero temperature: Flex2
- Yasumichi Aoki (RIKEN)
QCD at non-zero temperature: TR5
- Masakiyo Kitazawa (Yukawa Institute for Theoretical Physics)
In this work, we study the Chiral Magnetic Effect (CME) from lattice QCD simulations considering two different scenarios, in particular focusing on the leading-order coefficient of the vector current in a chiral chemical potential expansion. In the first scenario, we consider continuum extrapolated QCD with 2+1 flavors of improved staggered fermions, a system in thermal equilibrium, with a...
We present the first lattice QCD results of quadratic fluctuations and correlations of conserved charges in (2+1)-flavor lattice QCD in the presence of a background magnetic field. The simulations were performed using the Highly Improved Staggered Quarks with physical pion mass $m_\pi$ = 135 MeV on $N_\tau=8$ and 12 lattices. We find that the correlation between net baryon number and electric...
The shear viscosity of the quark-gluon plasma (QGP) plays a crucial role in interpreting current measurements from heavy-ion collisions and are key inputs to hydro-dynamical models. The interest in shear viscosity also lies in the fact that QGP is the most ideal fluid ever observed and has the shear viscosity to entropy ratio ($\eta / s$) close to the theoretical bound $\eta / s \geq 1/ 4 \pi$...
Thermal photon production in heavy-ion collisions is a crucial tool for studying quark-gluon plasma (QGP), as photons carry information about the local environment from the point of creation. The thermal photon production rate from an equilibrated plasma is proportional to the spectral function in the vector channel. We estimate the photon rate from the difference between the transverse and...
The real time evolution of a heavy particle in a strongly coupled plasma is determined by transport coefficients, such as the diffusion coefficient $\kappa$ and $\gamma$. While, in the fundamental representation, the heavy quark diffusion is well studied, the diffusion of adjoint quarks or quarkonium has not yet been fully explored on the lattice. In a suitable NREFT description of QCD,...
The sphaleron rate is a key phenomenological quantity both for the axion thermal production in the early Universe and the Chiral Magnetic Effect occurring in the Quark-Gluon Plasma in presence of a background magnetic field. In this talk we present an extension of our recent determination of the sphaleron rate, both in pure gauge and full QCD, based on the determination of the two-point...
I discuss chiral symmetry restoration in the chiral limit of QCD with two quark flavours of mass $m$, focussing on its consequences for scalar and pseudoscalar susceptibilities, and on the resulting constraints on the Dirac spectrum. I show that $\mathrm{U}(1)_A$ symmetry remains broken in the $\mathrm{SU}(2)_A$ symmetric phase if the spectral density $\rho(\lambda;m)$ develops a singular...
We present the first non-perturbative determination of the magnetic field dependence of the QCD topological susceptibility for temperatures in the crossover region. We use 2+1 flavours of improved staggered quarks at the physical point. In our study we employ a reweighting of the fermion determinant to reduce the discretisation effects and obtain a controlled continuum limit. The...
In this work we probe the QCD Anderson transition by studying spectral distributions of the massless overlap operator on gauge configurations created by the twisted mass at finite temperature collaboration (tmfT) with 2+1+1 flavors of dynamical quarks and the Iwasaki gauge action. We assess finite-size and discretization effects by considering two different lattice spacings and several...
Low-lying Dirac modes become localized at the finite-temperature transition in QCD and other gauge theories, indicating a connection between localization and deconfinement. This phenomenon can be understood through the "sea/islands" picture: in the deconfined phase, modes become trapped on "islands" of Polyakov loop fluctuations within a "sea" of ordered Polyakov loops.
To test the...
Understanding the screening mass of pseudoscalar mesons at finite temperature and magnetic field is crucial for comprehending the behavior of strongly interacting matter under extreme conditions, such as those found in the early universe or inside neutron stars. Additionally, in heavy ion collisions, strong magnetic fields are generated, which could significantly influence the properties of...
The chiral phase transition in QCD is frequently studied by either
locating the inflection point of a suitably renormalized order
parameter or the extrema of chiral susceptibilities as function of the
light quark masses. In the limit of vanishing light quark masses
their scaling behaviour is dominated by scaling functions and critical
exponents that are unique for a given universality...
We update the study of three-flavour QCD phase transition with Mobius domain-wall fermions at zero chemical potential. The simulations are performed on Nt=12 lattices with aspect ratio between 2 and 4 for a variety of quark masses at a lattice spacing 0.13 fm. A large volume lattice of 48^3x12 is added to clarify the nature of transition by measuring the volume dependence of chiral...
I will talk about our recent results on the nature of charm degrees of freedom in hot strong interaction matter based on lattice QCD calculations of the second and fourth-order cumulants of charm fluctuations, and their correlations with net baryon number, electric charge, and strangeness fluctuations. I will begin by showing that below the chiral crossover temperature, $T_{pc}$,...
We report on the investigation of the thermodynamics of 2+1 flavor QCD along the lines of constant physics (LCP) tuned on and near the physical point with Mรถbius domain wall fermions. The study is aiming to explore the temperature range covering (pseudo-) criticality for two lattice spacings with $N_t=12$ and $16$. In our simulations the lattice spacing covers 1.4 $> a >$ 0.6 fm, where the...
Understanding how the properties of heavy mesons change as temperature increases is crucial for gaining valuable insights into the properties of the quark-gluon plasma. The information about meson mass and decay width is encoded in the meson spectral function, which, in principle, can be extracted from Euclidean correlation functions via Laplace transformation. Unfortunately, this inverse...
We will discuss our recent results for the thermal mass and width of bottomonium. A well-known challenge for the lattice community is calculating the spectral function from the Euclidean correlator. We have approximated the spectral function and derived the mass and width of particles through the time derivatives of the lattice correlator.
We have focused on extracting the properties of...
Bottomonia plays a crucial role in our understanding of the quark gluon plasma phase. It is thus essential to have a thorough basis which which to examine bottomoniun states. We thus present lattice non-relativistic QCD calculations of bottomonia at temperatures in the range $T\in[47,\,380]$ MeV using the FASTSUM Generation 2L anisotropic $N_f = 2 + 1$ ensembles. The use of a basis of smeared...
Lattice nonrelativistic QCD study of ground and excited bottomonia at finite temperatures is presented. The correlation functions are computed using extended bottomonium operators with wave-function optimizing for excited states and also Gaussian shape for ground S- and P-wave states. Lattice calculations are performed on (2+1)-flavor gauge configurations using HISQ action near physical point...
Quarkonia, the bound states of heavy quark-antiquark pairs, are crucial probes for studying quark-gluon plasma (QGP). The color screening properties of the QGP weaken the interactions between quark-antiquark pairs, leading to the suppression of quarkonia yields within the QGP. Here, we present some preliminary results on the fate of quarkonia bound states in the QGP by performing spectral...
The latent heat of the first-order deconfinement phase transition in SU(3) Yang-Mills theory can be determined from the discontinuity in the entropy density $s(T_c)$ at the critical temperature $T_c$. Using shifted boundary conditions, the entropy density becomes a primary thermal observable that can be computed from the expectation value of the space-time components $T_{0k}$ of the...
We discuss a recently introduced strategy to study non-perturbatively thermal QCD
up to temperatures of the order of the electro-weak scale, combining step scaling
techniques and shifted boundary conditions. The former allow to renormalize the
theory for a range of scales which spans several orders of magnitude with a moderate
computational cost. Shifted boundary conditions remove the need...
We present two non-perturbative strategies for computing the QCD Equation of State up to high temperatures, designed to be computationally efficient and based on shifted boundary conditions. Using Monte Carlo lattice simulations of QCD with 3 flavours of O(a)-improved Wilson massless quarks and the Wilson gauge action, we obtain results for the entropy density $s(T)/T^3$ in the continuum...
In this talk we detail the non-perturbative computation of the entropy density in QCD with $N_f=3$ massless O($a$)-improved Wilson fermions, in a temperature range from a few GeV up to the Electro-Weak scale. This contribution complements the companion talk (part 1) where the theoretical strategy and main results for determining the QCD Equation of State are reported. We formulate QCD in a...
We present the first detailed investigation of the baryonic screening masses with nucleon quantum numbers in the extremely high temperature regime of QCD. Baryonic screening masses have been computed non-perturbatively on the lattice in the range of temperature from 1 GeV up to 160 GeV as well as at next-to-leading order in the dimensionally reduced effective theory, where quarks are treated...
At extreme temperatures the behavior of hadronic matter depends on the
type of excitations that can exist in a thermal medium. This information
is encoded within the spectral functions of hadronic correlators. Using
lattice data for correlators of pseudo-scalar meson operators in $2+1$
flavour QCD we investigate the presence of particle-like excitations,
so-called thermoparticles. In...
