PaperPanorama

HEP Lattice·hep-lat

Wed·Aug 12, 2026

5 papers—2 primary·3 cross-listed

All5Primary2Cross-lists3
  1. 01

    Vacuum polarization in QED with an electromagnetic background from the lattice

    En-Hung Chao🇺🇸

    We propose a framework to determine the vacuum polarization functions in QED in the presence of an electromagnetic background field in the spacelike region on the lattice. This method consists in reweighting lattice Monte Carlo data generated without the background with the fermion determinant ratio evaluated in the continuous spacetime using worldline formalism. This proposal can be further extended to other applications in lattice gauge theory, such as QCD in finite chemical potential.

    hep-lat0 citations
  2. 02

    Approximating Grassmann valued path integrals with radial basis function neural networks

    Gábor Balassa🇰🇷

    Solving path integrals in quantum field theories often involves the numerical handling of noncommuting Grassmann fields, which is in many cases a highly nontrivial and numerically inefficient task, especially in large systems and at higher dimensions. In this paper a radial basis function type neural network construction is used to approximate fermionic path integrals that include local couplings in their hopping terms. By isolating the interaction terms from the purely fermionic components using a radial basis function expansion, the path integral can be approximated by a few percent accuracy even for very large lattice sizes. The method has been developed and tested using staggered fermions in one, and in two dimensions, through calculating the partition functions, and expectation values.

    hep-lathep-phPRD(2026)·0 citations
  3. 03

    Calibrated correlation between heavy-quark masses and Hadronic Vacuum Polarization observables at the precision frontier

    Arnau Beltran🇩🇪 · Pere Masjuan🇪🇸 · Antonio Rivera🇪🇸

    The theoretical prediction of the muon anomalous magnetic moment depends crucially on the Hadronic Vacuum Polarization (HVP), and the tension between its dispersive and lattice-QCD determinations remains unresolved. We show that part of this puzzle can be addressed in the heavy-quark sector, where both descriptions are theoretically clean, by recognizing that the heavy-quark mass and its contribution to are not independent quantities: both follow from integrals of the same hadronic spectral function, differing only in their integration kernel. Promoting this kernel to a free choice within the relativistic QCD Sum Rules used to determine heavy-quark masses, we break with the conventional notion of a single valid sum rule and instead determine the mass and its HVP contribution simultaneously, from a common, self-consistent framework. This intrinsic construction exploits the anticorrelation between the two quantities to sharpen the final uncertainty, and turns the residual disagreement between the perturbative and hadronic descriptions of the observable into a direct observable-specific diagnostic of residual theory/model dependence, including duality-violation and continuum-modeling effects, unavailable to a determination of the mass alone. We obtain at leading and at next-to-leading order, for charm and bottom contributions, respectively. We compare our next-to-leading-order results with its first available lattice determination, finding good agreement in the charm sector. As a byproduct, we obtain MeV and MeV, with unprecedented phenomenological precision.

    ↳ hep-phhep-lat1 citation
  4. 04

    State-Dependent Visibility of Non-Commutative Ordering in Quantum Dynamics

    Ji-Chong Yang🇨🇳 · Gui-Qi Hu

    A nonzero commutator proves that two orderings differ as operators, but it does not ensure that a physical state can reveal the difference. We ask when non-Abelian ordering information becomes dynamically invisible. For Hermitian operators and , we compare the evolutions generated by the opposite-order products and , and define their operational visibility from the minimum overlap of the output states over a normalized time window. This visibility bounds the difference produced by the two orderings in every observable on the chosen state. An exact one-qubit solution shows that the same fixed pair can be perfectly invisible in one state and visible in another. We then keep the ordered generators fixed and vary only the many-body ground state across a quantum phase transition. The same ordering difference is nearly invisible in one regime and clearly visible in the other. Moreover, states with identical leading quadratic decay can develop sharply different finite-time visibility because their first distinction appears at higher order. The effect persists across distinct operator pairs and coefficient perturbations. Thus dynamical Abelianization is a property of the state-dependent process, i.e., non-Abelian ordering information can become operationally inaccessible even though the underlying operators remain non-commuting.

    ↳ quant-phhep-lat0 citations
  5. 05

    QCD Vacuum in an Inhomogeneous Magnetic Field

    Prabal Adhikari🇺🇸 · Brian C. Tiburzi🇺🇸

    The effect of an inhomogeneous magnetic field on the QCD vacuum is addressed using the framework of chiral perturbation theory. The magnetic field is chosen to be localized along one spatial direction, with a profile for which the underlying quantum mechanical problem is exactly solvable. Particular attention is paid to regularization and renormalization using dimensional regularization. While the non-vanishing gradient of the magnetic field requires additional operators in chiral perturbation theory, their effect occurs at next-to-next-to-leading order in the chiral expansion. Consequently, the magnetic field dependence of equilibrium vacuum observables can be determined at next-to-leading order without undetermined parameters. We compute the zero-temperature free energy and chiral condensate for the inhomogeneous background, both as integrated quantities as well as spatially resolved local observables. Comparison with locally constant approximations enables a direct probe of the spatial response and nonlocal structure of the magnetized QCD vacuum. We additionally derive the induced vacuum current associated with the inhomogeneity of the magnetic field.

    ↳ hep-phhep-latnucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE