Fri·Nov 26, 2021Friday·November 26, 2021

1. 01*

   Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear $\sigma$-model

   John Bulava🇩🇪 · Maxwell T. Hansen🇬🇧 · Michael W. Hansen🇦🇹 · Agostino Patella🇩🇪 · Nazario Tantalo🇮🇹

   This work employs the spectral reconstruction approach of Ref. [1] to determine an inclusive rate in the $1+1$ dimensional O(3) non-linear $\sigma$-model, analogous to the QCD part of $e^{+}{e}^{-}\to \mathrm{hadrons}$. The Euclidean two-point correlation function of the conserved current $j$ is computed using Monte Carlo lattice field theory simulations for a variety of spacetime volumes and lattice spacings. The spectral density of this correlator is related to the inclusive rate for $j\to \mathrm{X}$ in which all final states produced by the external current are summed. The ill-posed inverse problem of determining the spectral density from the correlation function is made tractable through the determination of smeared spectral densities in which the desired density is convolved with a set of known smearing kernels of finite width $ϵ$. The smooth energy dependence of the underlying spectral density enables a controlled $ϵ\to 0$ extrapolation in the inelastic region, yielding the real-time inclusive rate without reference to individual finite-volume energies or matrix elements. Systematic uncertainties due cutoff effects and residual finite-volume effects are estimated and taken into account in the final error budget. After taking the continuum limit, the results are consistent with the known analytic rate to within the combined statistical and systematic errors. Above energies where 20-particle states contribute, the overall precision is sufficient to discern the four-particle contribution to the spectral density.

   hep-latJHEP(2022)·72 citations
2. 02*

   Nucleon isovector form factors from physical-mass 2+1-flavor dynamical domain-wall QCD

   Shigemi Ohta (KEK, for the LHP, RBC, and UKQCD Collaborations)🇯🇵

   The current status is reported of joint lattice numerical calculations by LHP and RBC collaborations of isovector nucleon form factors using 2+1-flavor physical-mass domain-wall fermions ensemble at a lattice cutoff $a^{-1}$ of 1.730(4) GeV and spatial volume of $(La=\text{mbox}5.471(13)\mathrm{fm}{)}^3$ generated jointly by RBC and UKQCD collaborations.

   hep-latPoS(2022)·4 citations
3. 03*

   Bootstrapping Lattice Vacua

   Scott Lawrence🇺🇸

   This paper demonstrates the application of semidefinite programming to lattice field theories, showcasing spin chains and lattice scalar field theory. Requiring expectation values of manifestly positive semi-definite operators to be non-negative results in a lower bound on the ground-state energy of any quantum mechanical system, which can be made arbitrarily tight for systems described by finite-dimensional Hilbert spaces. Such bounds can be obtained directly in the infinite-volume limit. The process of optimizing these lower bounds also yields estimates for a chosen set of expectation values in the ground state.

   hep-lat26 citations
4. 04*

   Scaling region of the 3D Ising universality class in finite temperature QCD

   Michele Caselle🇮🇹 · Marianna Sorba🇮🇹

   We introduce a universal combination of susceptibility and correlation length in the 3D Ising model, depending both on temperature and external magnetic field. Starting from a parametric representation of the equation of state, we study its behaviour close to the critical point. The results we derive can be used as a sort of "reference frame" to chart the scaling region of the 3D Ising universality class. More specifically, we focus on instances of Ising behaviour in finite temperature QCD and, among these, we are particularly interested on the critical ending point in the finite density, finite temperature QCD phase diagram. In this context, Monte Carlo simulations are not possible and it is particularly difficult to disentangle "magnetic-like" from "thermal-like" observables, thus an explicit charting of the critical region could be useful for a direct comparison of experimental results with QFT/Statmech predictions.

   hep-latcond-mat.stat-mechhep-thPoS(2022)·0 citations
5. 05*

   Flux tube profiles in two-color QCD at low temperature and high density

   Katsuya Ishiguro🇯🇵 · Kei Iida🇯🇵 · Etsuko Itou🇯🇵

   We investigate the temperature and density dependence of the color flux tube structure of dense two-color QCD with $N_f=2$ Wilson fermions by using a lattice simulation. From Refs. [1] and [2], we have already clarified the rich phase structure in the low temperature region, including the hadronic and superfluid phases. In this study we measure the quark-antiquark potential and color flux tube profiles in such a low temperature region and find that even in the high density superfluid phase, the color electric field is squeezed into a flux tube as in the low density hadronic phase.

   hep-latPoS(2022)·10 citations
6. 06*

   The SU(N) running coupling in the twisted gradient flow scheme and volume independence

   Jorge Luis Dasilva Golan🇪🇸 · Margarita Garcia Perez🇪🇸 · Alberto Ramos🇪🇸

   We report on an ongoing study of the running coupling of SU(N) pure Yang-Mills theory in the twisted gradient flow scheme (TGF). The study exploits the idea that twisted boundary conditions reduce finite volume effects, leading to an effective size in the twisted plane that combines the number of colours and the torus period. We test this hypothesis by computing the TGF running coupling and the SU(N) $\Lambda -$ parameter on asymmetric lattices of size $(NL{)}^2{L}^2$ for various gauge groups. Finite volume effects are monitored by analyzing the coupling in different planes and by comparing results at different number of colours.

   hep-latPoS(2022)·2 citations
7. 07*

   Lattice QCD with an inhomogeneous magnetic field background

   B. B. Brandt🇩🇪 · F. Cuteri🇩🇪 · G. Endrődi🇩🇪 · G. Markó🇩🇪 · A. D. M. Valois🇩🇪

   The magnetic fields generated in non-central heavy-ion collisions are among the strongest fields produced in the Universe, reaching magnitudes comparable to the scale of the strong interactions. Backed by model simulations, the resulting field is expected to be spatially modulated, deviating significantly from the commonly considered uniform profile. To improve our understanding of the physics of quarks and gluons under such extreme conditions, we use lattice QCD simulations with $2+1$ staggered fermion flavors with physical quark masses and an inhomogeneous magnetic background for a range of temperatures covering the QCD phase transition. We assume a $1/{\cosh }^2$ function to model the field profile and vary its strength to analyze the impact on the computed observables and on the transition. We calculate local chiral condensates, local Polyakov loops and estimate the size of lattice artifacts. We find that both observables show non-trivial spatial features due to the interplay between the sea and the valence effects.

   hep-lathep-thnucl-thPoS(2022)·6 citations
8. 08*

   Fractionalized holes in one-dimensional ${\mathbb{Z}}_2$ gauge theory coupled to fermion matter -- deconfined dynamics and emergent integrability

   Aritra Das🇮🇳 · Umberto Borla🇩🇪 · Sergej Moroz🇩🇪

   We investigate the interplay of quantum one-dimensional discrete ${\mathbb{Z}}_2$ gauge fields and fermion matter near full filling in terms of deconfined fractionalized hole excitations that constitute mobile domain walls between vacua that break spontaneously translation symmetry. In the limit of strong string tension, we uncover emergent integrable correlated hopping dynamics of holes which is complementary to the constrained XXZ description in terms of bosonic dimers. We analyze numerically quantum dynamics of spreading of an isolated hole together with the associated time evolution of entanglement and provide analytical understanding of its salient features. We also study the model enriched with a short-range interaction and clarify the nature of the resulting ground state at low filling of holes and identify deconfined hole excitations near the hole filling ${\nu }^h=1/3$.

   ↳ cond-mat.str-elcond-mat.quant-gashep-lathep-thPRB(2023)·8 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.