Fri·Nov 12, 2021Friday·November 12, 2021

1. 01*

   Precision bottomonium properties and b quark mass from lattice QCD

   C. T. H. Davies🇬🇧 · D. Hatton🇬🇧 · J. Koponen🇩🇪 · G. P. Lepage🇺🇸 · A. T. Lytle🇺🇸

   As tests of QCD in the bottomonium system, we give the most accurate results to date for the ground-state hyperfine splitting and the ${\rm Y}$ leptonic width from full lattice QCD. These quantities are both accurately known from experiment, so can provide a good test of $b$ physics, but previous lattice results have been rather imprecise. We also test the impact on these quantities of the $b$ quark's electric charge. Our results are: $M_{{\rm Y}}-M_{{\eta }_b}=$ 57.5(2.3)(1.0) MeV (where the second uncertainty comes from neglect of quark-line disconnected correlation functions) and decay constants, $f_{{\eta }_b}=$ 724(12) MeV and $f_{{\rm Y}}=$ 677.2(9.7) MeV, giving $\Gamma ({\rm Y}\to e^{+}{e}^{-})=$ 1.292(37)(3) keV. We also give a new determination of the ratio of the masses for $b$ and $c$ quarks that is completely nonperturbative in lattice QCD and includes the calculation of QED effects for the first time. This gives a result for the $b$ quark mass of ${\overline{m}}_b({\overline{m}}_b,n_f=5)=$ 4.202(21) GeV.

   hep-latPoS(2022)·1 citation
2. 02*

   Lee-Yang edge singularities in lattice QCD : A systematic study of singularities in the complex ${\mu }_B$ plane using rational approximations

   Simran Singh🇮🇹 · Petros Dimopoulos🇮🇹 · Lorenzo Dini🇩🇪 · Francesco Di Renzo🇮🇹 · Jishnu Goswami🇩🇪 · Guido Nicotra🇩🇪 · Christian Schmidt🇩🇪 · Kevin Zambello🇮🇹 · Felix Ziesche🇩🇪

   A new approach is presented to explore the singularity structure of lattice QCD at imaginary chemical potential. Our method can be seen as a combination of the Taylor expansion and analytic continuation approaches. Its novelty lies in using rational (Padé) approximants for studying Lee Yang edge singularities. The motivation for using rational approximants will be exhibited. We will provide some confidence in our approach based on numerical experiments performed on well-motivated "toy models". Our focus lies in identifying singularities of the net-baryon number density in the complex ${\mu }_B$ plane. To this end we have found signatures of the Roberge-Weiss critical point(and Chiral singularities -- subject to some caveats). In this contribution we will discuss the setup, simulation parameters and results obtained for 2+1 flavor QCD in the complex ${\mu }_B/T$ plane.

   hep-latPoS(2022)·10 citations
3. 03*

   Nucleon Axial Form Factor from Domain Wall on HISQ

   Aaron S. Meyer🇺🇸 · Evan Berkowitz🇺🇸 · Chris Bouchard🇬🇧 · Chia Cheng Chang🇯🇵 · M.A. Clark🇺🇸 · Ben Hörz🇺🇸 · Dean Howarth🇺🇸 · Christopher Körber🇩🇪 · Henry Monge-Camacho🇨🇷 · Amy Nicholson🇺🇸 · Enrico Rinaldi🇺🇸 · Pavlos Vranas🇺🇸 · André Walker-Loud🇺🇸

   The Deep Underground Neutrino Experiment (DUNE) is an upcoming neutrino oscillation experiment that is poised to answer key questions about the nature of neutrinos. Lattice QCD has the ability to make significant impact upon DUNE, beginning with computations of nucleon-neutrino interactions with weak currents. Nucleon amplitudes involving the axial form factor are part of the primary signal measurement process for DUNE, and precise calculations from LQCD can significantly reduce the uncertainty for inputs into Monte Carlo generators. Recent calculations of the nucleon axial charge have demonstrated that sub-percent precision is possible on this vital quantity. In these proceedings, we discuss preliminary results for the CalLat collaboration's calculation of the axial form factor of the nucleon. These computations are performed with Möbius domain wall valence quarks on HISQ sea quark ensembles generated by the MILC and CalLat collaborations. The results use a variety of ensembles including several at physical pion mass.

   hep-latPoS(2022)·12 citations
4. 04*

   Another look at the three-gluon vertex in the minimal Landau gauge

   Guilherme T. R. Catumba🇪🇸 · Orlando Oliveira🇵🇹 · Paulo J. Silva🇵🇹

   The lattice three-gluon vertex in the Landau gauge is revisited using a large physical volume $\sim (8\text{fm}{)}^4$ and a large statistical ensemble. The improved calculation explores the symmetries of the hypercubic lattice to reduce the statistical uncertainties and addresses the evaluation of the lattice artefacts. Special attention is given to the low energy behaviour of the vertex and its relation to ghost dominance.

   hep-latPoS(2022)·8 citations
5. 05*

   Nonperturbative excitations in overoccupied gluon plasmas

   Kirill Boguslavski🇦🇹

   Motivated by the early-time dynamics of the quark-gluon plasma in high-energy heavy-ion collisions, we extract gluonic spectral functions of overoccupied gauge theories far from equilibrium using classical-statistical lattice simulations and linear response theory. In 3+1 dimensions we find that the spectral function exhibits quasiparticle excitations at all momenta that are mostly consistent with perturbative hard-thermal loop predictions, while partially showing nonperturbative deviations. In contrast, the structure of excitations in 2+1 dimensions is nontrivial and nonperturbative. These nonperturbative interactions lead to broad excitation peaks in the spectral function, demonstrating the absence of soft quasiparticles in these theories. This also suggests that there may be significant nonperturbative corrections present in systems with large momentum anisotropy, which are relevant to phenomenological applications in heavy-ion collisions.

   hep-lathep-phnucl-thPoS(2022)·0 citations
6. 06*

   Color confinement and restoration of residual local gauge symmetries

   Kei-Ichi Kondo🇯🇵 · Naoki Fukushima🇯🇵

   All colored particles including dynamical quarks and gluons are confined if the color confinement criterion proposed by Kugo and Ojima is satisfied. The criterion was obtained under the gauge fixing of the Lorenz type. However, it was pointed out that the Kugo-Ojima criterion breaks down for the Maximal Abelian gauge, which is quite strange in view of the fact that quark confinement has been verified according to the dual superconductivity caused by magnetic monopole condensations. In order to make a bridge between color confinement due to Kugo and Ojima and the dual superconductor picture for quark confinement, we investigate a generalization of the color confinement criterion to obtain the unified picture for confinement. We show that the restoration of the residual local gauge symmetry which was shown in the Lorenz gauge by Hata to be equivalent to the Kugo-Ojima criterion indeed occurs in the Maximal Abelian gauge for the SU(N) Yang-Mills theory in two-, three- and four-dimensional Euclidean spacetime once the singular topological configurations of gauge fields are taken into account. This result indicates that the color confinement phase is a disordered phase caused by non-trivial topological configurations irrespective of the gauge choice. As a byproduct, we show that the compact U(1) gauge theory can have the disordered confinement phase, while the non-compact U(1) gauge theory has the deconfined Coulomb phase.

   ↳ hep-thhep-lathep-phPTEP(2022)·4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.