Conveners
Standard Model parameters: TR5
- Aida El-Khadra (University of Illinois Urbana-CHampaign)
Standard Model parameters: TR6
- Chik Him Wong (University of Wuppertal)
Standard Model parameters: TR6
- Amarjit Soni (BNL)
Standard Model parameters: TR7
- Stefan Sint (Trinity College Dublin)
We present results for the pseudoscalar decay constants $f_{\rm D_{(\rm s)}}$ from the RQCD and ALPHA collaboration's joint effort. Our calculations are based on the $N_{\rm f} = 2+1$ CLS ensembles at six values of the lattice spacing in the range from a = 0.098 fm down to a = 0.039 fm, with pion masses spanning from approximately 420 MeV to below the physical mass. The ensembles lie on three...
We report our progress in determining the form factors in semileptonic decays of D mesons. We work with overlap valence fermions on 2+1-flavor domain wall fermion configurations. The lattice is of size 32^3*64 and with an inverse lattice spaicng 1/a=2.383(9) GeV. Renormalizations of current operators are done nonperturbatively.
The inclusive hadronic decays of the $\tau$ lepton are of great interest as they provide an alternative method for determining the CKM matrix elements $V_{\rm ud}$ and $V_{\rm us}$. In this talk, I will present the results of the ETM Collaboration on the inclusive hadronic decay rate of the $\tau$. Our results have been obtained in $N_{f}=2+1+1$ QCD using the novel HLT method, which...
RI/MOM renormalization scheme is known to have poor perturbative convergence for the scalar current and then would not be very suitable for precise quark mass renormalization. I shall present our recent investigation on suppressing this uncertainty and also renormalized quark masses with this strategy using the overlap and clover fermions.
I propose a new method to determine quark mass using the vacuum expectation values (VEVs) of bilinear operators of the flowed quark field. This method allows for the determination of quark mass through a comparison of its perturbative calculation with its lattice data, where a precise measurement is expected, without gauge dependence or UV divergences. In this context, I present preliminary...
We report on our update to [JHEP 08 (2022) 220] on the hadronic running of electroweak couplings from $O(a)$-improved Wilson fermions with $N_f=2+1$ flavours. The inclusion of additional ensembles at very fine lattice spacings together with a number of techniques to split the different contributions for a better control of cutoff effects allow us to achieve improved precision. We employ two...
We report on our Ward identity determination of the $\mathrm{O}(a)$ improvement coefficient for the flavour singlet scalar density, namely $g_\mathrm{S}$, from three-flavour lattice QCD with Wilson-clover fermions and the tree-level Symanzik improved gauge action. We employ five couplings, $g_0^2 \in [1.5,1.77]$, that cover the range used in large-volume CLS simulations.
While $g_\mathrm{S}$...
We present results on the improvement coefficient of the non-singlet axial-vector current, with particular emphasis on imposing improvement conditions in the chiral limit and at the flavour-symmetric point.
For its determination, the established Ward-identity method is employed in $N_{\rm f}=3$ QCD with stabilised Wilson-Clover fermions.
We simulate with Schrödinger functional boundary...
We present preliminary results for the Renormalization Group (RG) running of the complete basis of $\Delta F = 2$ four-fermion operators in QCD with $N_\mathrm{f} = 3$ dynamical massless flavors. We use $O(a)$-improved Wilson fermions in a mixed action setup, with chirally rotated Schrödinger functional (𝜒SF) boundary conditions for the valence quarks and Schrödinger functional (SF) boundary...
We present the scalar, pseudoscalar, vector and axial-vector renormalization constants with the regularization independent momentum subtraction (RI/MOM) scheme as the intermediate scheme using domain wall fermion on 2+1 flavors ensembles from RBC/UKQCD collaboration and highly improved staggered quark on 2+1+1 flavors ensembles from MILC. A two-step matching method is used to reduce the...
The strong coupling constant $\alpha_s$ can be obtained from the static energy as shown in previous lattices studies. For short distances, the static energy can be calculated both on the lattice with the use of Wilson line correlators, and with the perturbation theory up to three loop accuracy with leading ultrasoft log resummation. Comparing the perturbative expression and lattice data allows...
In this talk we will investigate the approach to the
continuum limit using different gauge actions. We will argue that
solid and precise QCD calculations need to reach lattice spacings
finer than the current standard, or that several actions need to be
consider for a proper estimate of the systematic. Flow scales for
different actions will be determined. Together with lattice
...
We give an update and final result for the determination of the scales $r_0$, $r_1$, and $\frac{r_0}{r_1}$ for 2 + 1 flavour QCD ensembles generated by CLS and calculated from an improved definition of the static force measured using Wilson loops. This update includes full control over systematic and full statistics with various continuum and chiral extrapolations of data covering pion masses...
We report about an update of a scale setting procedure of a mixed action setup consisting of $N_f=2+1$ flavours of $O(a)$ improved Wilson sea quarks, based on CLS ensembles, and Wilson twisted mass valence quarks at maximal twist. We employ as external input the isoQCD masses and decay constants of pions and kaons, and the gradient flow scale $t_0$ as an intermediate scale. The analysis...
We discuss recent progress on determining the gradient flow scales t0 and w0 on the 2+1+1 HISQ ensembles generated by the MILC collaboration. For the relative scale setting we explore several discretization schemes of the action density for the flow and observable. For the absolute scale setting, we report some preliminary results on the Omega baryon mass computation with HISQ.
We recently introduced and tested the application of the infinite volume based gradient flow for the scale dependent renormalization of the strong coupling. Recent developments of this alternative approach are reported for the high precision determination of the beta-function and the physical scale of the $\Lambda_{\bar{MS}}$ parameter in QCD with three massless flavors and its Yang-Mills limit.
I will present a precise determination of the Ω baryon mass in lattice units at seven lattice spacings down to a ~ 0.048 fm with N_f=2+1+1 staggered quarks, including QED and strong-isospin corrections. We perform these measurements by solving the Generalized Eigenvalue Problem, adapted to staggered fermions to fully resolve the negative parity and excited states. The measurements are then...
