PaperPanorama

HEP Lattice·hep-lat

Fri·Jun 26, 2026

4 papers—2 primary·2 cross-listed

All4Primary2Cross-lists2
  1. 01

    Isospin breaking corrections to a lattice QCD calculation of

    Norman H. Christ🇺🇸 · Erik Lundstrum🇺🇸

    Because of the rule, the effects of electromagnetism and the isospin-breaking light quark mass difference on the direct CP violation parameter may be as large as 25\% and are consequently of immediate interest. In a lattice QCD calculation the effects of isospin breaking on the various features of kaon decay can be clearly distinguished and those effects enhanced by the rule on explicitly identified. We show that all such enhanced effects can be captured in a QCD + QED lattice calculation in which the exchanged photon has an energy in an accessible, intermediate range between 0.5-2.0 GeV. Short-distance effects (), usually treated in QCD and electroweak perturbation theory, are not enhanced by the rule, beyond the well-understood contribution of the two electroweak penguin operators. Infrared photons do not contribute to while low-energy photons ( GeV) are not rule enhanced or are suppressed by one order in chiral perturbation theory (ChPT). An explicit ChPT estimate of this low-energy-photon contribution, a contribution that is difficult to determine in a finite-volume lattice calculation, suggests that the effect on is on the order of 0.5\%.

    hep-lathep-ph0 citations
  2. 02

    Performance of Low Mode Averaging on Twisted-Mass Fermion Ensembles at the physical pion mass point

    Constantia Alexandrou🇨🇾 · Simone Bacchio🇨🇾 · Antonio Evangelista🇨🇾 · Roberto Frezzotti🇮🇹 · Francesca Margari🇮🇹 · Francesco Sanfilippo🇮🇹 · Christian Schneider🇨🇾

    We study the performance of low-mode averaging (LMA) on twisted-mass fermion ensembles at near-physical quark masses, assessing both its theoretical framework and practical cost-effectiveness in modern lattice QCD. In particular, we present a numerical study of light-quark meson and baryon observables. For mesons, we analyse two-point functions, including the vector-vector correlator relevant for the hadronic vacuum polarisation contribution to the muon anomalous magnetic moment, comparing two implementations of LMA: an exact approach based on explicit low modes and an approximate, high-statistics variant using multigrid techniques. For baryons, we restrict to the exact approach and study both two- and three-point functions, quantifying the resulting noise and cost reductions at large Euclidean times. In addition, we compute the eigenvalue density of the massless Wilson operator and determine the renormalised chiral condensate via the Banks-Casher relation, obtaining for isospin-symmetric QCD at a scale in the scheme, with an uncertainty dominated by the chiral extrapolation. Additionally, from the pion-mass dependence of , we extract the scale-independent low-energy constant .

    hep-lat0 citations
  3. 03

    Axial-Vector Lattice Benchmarks Reveal a Common Medium Response of Meson Screening in Hot QCD

    Jie Ren🇨🇳 · Chen Chen🇨🇳 · Fei Gao🇨🇳 · Si-xue Qin🇨🇳

    Meson screening masses trace the evolution of hadronic correlations toward quasi-free quark--antiquark screening in hot QCD. Combining lattice QCD (LQCD) benchmarks with a symmetry-preserving Dyson--Schwinger baseline, we identify a flavor-dependent axial-vector quasi-free onset, : an operational high-temperature matching scale at which the axial-vector screening mass has approached the corresponding free-field value after ordinary chiral restoration or parity-partner convergence has set in. On the finite interval , independent light/strange and charm-containing lattice benchmarks are organized by a common medium-response function with one flavor-sector parameter. One axial-vector point fixes this parameter; the remaining axial-vector data test its temperature dependence, and vector screening masses validate it without vector input. A reduced-mass interpolation then yields lattice-testable quasi-free onsets and screening spectra for light-charm and bottom-containing sectors. The resulting onset scales provide common reference points for future lattice and continuum studies of meson dissolution across flavor.

    ↳ hep-phhep-exhep-latnucl-ex+10 citations
  4. 04

    Probing Probability Geometry with Schwinger--Dyson Identities: Score Mismatch, Fisher Information, and Configurational Temperature

    Anosh Joseph🇿🇦

    We develop a geometric interpretation of Schwinger--Dyson identities by showing that their violations are controlled by a single score-mismatch field . For an arbitrary sampled probability distribution and equilibrium measure , every Schwinger--Dyson violation is determined by , which characterizes the departure from equilibrium. Each Schwinger--Dyson identity measures a projection of this field onto a probe direction in configuration space. The relative Fisher information is its squared norm. This gives a universal bound relating Fisher information to the complete Schwinger--Dyson hierarchy, thus implying that convergence in Fisher information restores all Schwinger--Dyson identities. We further obtain a variational characterization of the relative Fisher information in terms of Schwinger--Dyson violations, leading to a natural tomographic interpretation in which increasingly rich families of probe fields encode progressively more information about the underlying probability distortion. The configurational temperature, within this framework, emerges as a distinguished Schwinger--Dyson probe. The Stein operators and score-function methods arise naturally from the same probability-geometric structure. The score-mismatch field, therefore, provides a unified geometric language for understanding Schwinger--Dyson identities, configurational temperature, Fisher information, and non-equilibrium sampling in stochastic processes.

    ↳ hep-thhep-lat2 citations

Affiliations

first authorsco-authorsvia INSPIRE