HEP Lattice·hep-lat

Tue·Aug 11, 2026Tuesday·August 11, 2026

8 papers—1 primary·7 cross-listed

01
Chemical Potential and Analytic Continuation for Non-Hermitian Lattice Fermions
Chen-Te Ma🇮🇳 · Hui Zhang🇨🇳
We introduce a chemical potential for non-Hermitian lattice fermions and show that, for even flavors with degenerate masses and paired chemical potentials $(μ, - μ)$ or $(i μ, i μ)$ , the Hybrid Monte Carlo algorithm is free of the sign problem. For one-dimensional free fermions, we demonstrate that the sign problem is a numerical rather than physical obstruction and derive the exact propagator, which is analytic at finite lattice spacing away from its poles but becomes non-analytic in the continuum limit. Finally, we use AI-assisted fitting to perform analytic continuation from imaginary to real chemical potentials.
hep-lat0 citations
02
Fuzzy Spectroscopy of Bound States in Massive Quantum Field Theories
Joseph Taylor🇬🇧 · Matthew Yusuf🇬🇧 · Zlatko Papić🇬🇧
Mesons and glueballs are paradigmatic bound states of confining quantum field theories (QFTs), but their nonperturbative spectroscopy in the continuum remains challenging beyond one spatial dimension. Here we perform such spectroscopy for the Ising QFT using a recently developed regularization based on noncommutative ``fuzzy'' geometry. On a thin fuzzy torus, we reproduce the universal low-lying $E_{8}$ meson masses of the magnetically perturbed $(1 + 1) D$ Ising QFT. By increasing the torus aspect ratio, we continuously track the second-lightest $E_{8}$ meson as the system effectively crosses over from 1D to 2D. On the 2D fuzzy torus and sphere, we find a subthreshold scalar level and above-threshold response features consistent with previous estimates of glueball masses. The same excitations are revealed away from equilibrium using quench dynamics. Our results establish fuzzy geometries as nonperturbative spectroscopic probes of massive QFTs, including their bound-state evolution through dimensional crossover.
↳ cond-mat.stat-mechcond-mat.str-elhep-lathep-th0 citations
03
Quest for an Understanding of Pion and Kaon Structure
Zhen-Ni Xu🇪🇸 · Daniele Binosi🇮🇹 · Craig D. Roberts🇨🇳 · José Rodríguez-Quintero🇪🇸
The emergence of massless (Nambu-Goldstone) bosons in association with a dynamically global broken symmetry is a long known and widespread phenomenon in physics. However, practically nothing is known about the expressions of Nambu--Goldstone boson character on the internal structure of these bound states. Indeed, their structure is often ignored. In strong interactions, pions and kaons are the (would-be) Nambu-Goldstone bosons and experiments underway or planned at existing or anticipated high-energy, high-luminosity facilities will gather data that it is hoped will enable maps to be drawn of their internal structure. Meanwhile, theory and phenomenology find themselves in something of a quagmire. Herein, we provide a snapshot of the current status, highlighting issues under debate and identifying areas that deserve greater attention so that best use can be made of what is likely to be a huge volume of data delivered in the next decade or so.
↳ hep-phhep-exhep-latnucl-ex+11 citation
04
Hamiltonian spectra in quantum computers through the generalized eigenvalue method
Valery Simonyan🇺🇸 · Greg Ridgway🇺🇸 · Paulo Bedaque🇺🇸
Quantum computers can generate real-time correlators of field theories. By adapting the generalized eigenvalue problem to these correlators, energy eigenvalues can be extracted directly. The method is tested using both classical simulations and quantum hardware, successfully resolving several low-lying energy levels in agreement with exact diagonalization. Comparison with an alternative spectrum determination based on the Fourier transform of correlators shows that the proposed approach is substantially more efficient.
↳ quant-phhep-latnucl-th0 citations
05
Correlated low-energy constants in large- $N_{c}$ chiral perturbation theory
Pere Masjuan🇪🇸
The combined chiral and large- $N_{c}$ expansion is increasingly employed in precision studies involving the $η$ and $η^{'}$ mesons, including recent applications to low-energy axion phenomenology within U(3) chiral perturbation theory. We point out that the operator structure of the large- $N_{c}$ chiral Lagrangian naturally induces correlated directions among the low-energy constants $(F_{0}, L_{4}, C_{16})$ and $(F_{0}, L_{6}, C_{20})$ , implying that phenomenological analyses determine correlated combinations of couplings rather than independent low-energy constants. Using the determination of the pion decay constant as an illustrative example, we reinterpret existing phenomenological and lattice determinations in terms of these correlated directions, showing that the well-known anticorrelation between $F_{0}$ and $L_{4}$ extends naturally to NNLO through $C_{16}$ . These correlated directions lead to a practical prescription for interpreting and propagating phenomenological determinations of the low-energy constants consistently within the combined chiral and large- $N_{c}$ framework.
↳ hep-phhep-lat0 citations
06
Quark spin-orbit correlations in spin-1 targets
Hyunwoo Kim🇰🇷 · June-Young Kim🇰🇷
The quark spin-orbit correlation probes the alignment of quark helicity with longitudinal kinetic orbital angular momentum inside a hadron. This correlation is defined by a QCD operator: the position moment of the asymmetric parity-odd quark energy-momentum tensor. The matrix element of this rank-two tensor decomposes into symmetric-traceless, antisymmetric, and trace parts. The symmetric-traceless part is matched to moments of axial generalized parton distributions. The QCD equations of motion relate the antisymmetric part to vector and tensor form factors and set the trace to zero. Using these relations, we derive two gauge-invariant sum rules for the spin-orbit correlation in a spin- $1$ hadron. One gives the correlation in an unpolarized target. The other gives its tensor-polarization dependence, which is absent for spin- $0$ and spin- $1/2$ targets. We estimate the unpolarized spin-orbit correlations for the $ρ$ meson and deuteron using existing lattice and phenomenological inputs, respectively.
↳ hep-phhep-lat0 citations
07
Effects of Born-Infeld Electrodynamics on Chiral Symmetry Restoration and Meson Susceptibilities in Holographic QCD
Hiwa A. Ahmed🇷🇴 · Peshwaz A. Abdoul🇮🇶
Within a holographic QCD framework, we numerically investigate chiral symmetry breaking and the associated phase transition at finite temperature and chemical potential. The model is constructed on a nonlinear charged Born-Infeld black hole background. The chiral condensate, extracted from the asymptotic behavior of the bulk scalar field, serves as the primary order parameter. At zero chemical potential, we find a chiral crossover transition for physical quark masses with a pseudocritical temperature of $T_{p c} = 0.1477$ GeV. In the chiral limit, the transition becomes first-order with a critical temperature of $T_{c} = 0.1337$ GeV. A critical strange quark mass of $m_{s} = 37$ MeV, at zero light quark mass, separates first- and second-order transition regions. For finite chemical potential ( $μ$ ) and a physical strange mass ( $m_{s} = 95$ MeV) with massless light quarks, the transition remains second-order, with $T_{c}$ decreasing as $μ$ increases. These results are further supported by the behavior of meson susceptibilities $(χ_{π} - χ_{σ})$ , which exhibit a rapid thermal decay and convergence across the phase boundary. Introducing the Born-Infeld parameter $β$ shifts the second-order phase boundary to higher temperatures for smaller $β$ (stabilizing the chirally broken phase) but does not alter the transition order or introduce a critical endpoint within the studied range. Our findings are consistent with previous soft-wall model studies and highlight the significant role of nonlinear bulk electrodynamics in modifying the chiral phase diagram.
↳ hep-phhep-lathep-th0 citations
08
The Living Guide of Machine Learning for Particle Physics
Claudius Krause🇦🇹 · Ramon Winterhalder🇮🇹 · Matthew Feickert🇺🇸 · Benjamin Nachman🇺🇸
We started the Living Review of Machine Learning for Particle Physics (HEP-ML Living Review) in 2020 as a community-maintained, near-comprehensive bibliography of machine learning in particle physics. The field was then growing faster than any single researcher could follow, finding the relevant papers was hard, and a structured, continuously updated reference paid off immediately. Since then the literature has grown by more than an order of magnitude, the methods reach far beyond the classification and generation tasks of the early years, and the community has built its own ecosystem of topic-specific reviews, benchmark papers, and software frameworks. The original model no longer serves this field well, and we can no longer sustain it. We therefore change direction. We freeze the Living Review as an archival reference covering the literature up to 1 June 2026, where it remains a stable record of the first phase of HEP-ML. A new resource, the HEP-ML Living Guide, replaces it. It does not list everything. It curates, it annotates, and it points readers to foundational and representative work, so that researchers can find their way into a mature and rapidly diversifying field. In this article we explain why we make this change and how the new resource works.
↳ hep-phhep-exhep-lathep-th+12 citations

Affiliations

first authorsco-authorsvia INSPIRE