PaperPanorama

HEP Lattice·hep-lat

Tue·Sep 15, 2026

6 papers—2 primary·4 cross-listed

All6Primary2Cross-lists4
  1. 01

    Thermal modifications of the B-meson spectrum

    Rachel Horohan D'Arcy🇮🇪 · Benjamin Jäger🇩🇰 · Seyong Kim🇰🇷 · Jon-Ivar Skullerud🇮🇪

    A first-principles investigation of heavy-light meson behaviour in hot QCD matter is essential for the interpretation of experimental results associated with open heavy flavour productions in relativistic heavy-ion collision experiments. Using anisotropic lattice ensembles from the FASTSUM collaboration with Nf=2+1 dynamical Wilson-clover fermions at non-zero temperatures, we study the B and B_s spectra at non-zero temperature. We use relativistic light quark propagators, while the b quark propagators are computed with a non-relativistic effective theory (NRQCD). We find that above T_c, thermal effects on the B meson states are more significant than those on the B_s states. Also, our results support the dissolution of the B-meson bound states above T_c.

    hep-lathep-phnucl-th0 citations
  2. 02

    Fermionic quantum field theories as probabilistic cellular automata in three dimensions

    Piotr Stanisław Topa🇺🇸

    Wetterich showed that certain 1+1D probabilistic cellular automata are equivalent to fermionic QFTs and posed the 3D construction as an open problem. We construct one: a layered automaton ("coincube") whose conversion blocks form the real quaternion representation of Cl(0,3), controlled by binary environment fields whose streaming outruns the carrier ("fresh tape") -- no bit is consulted twice, and the single-particle ensemble propagator equals the annealed Bloch operator at every time. Exact results: the step operator is unitary for an explicit complex structure; the local Grassmann action is extracted mechanically; the single-carrier excitation is a Weyl fermion with an isotropic leading cone (slope ratios 1 within errors, factorized transport excluded by >=10 error bars); at finite momentum the node carries a parity-odd anisotropy c(q)kx ky kz/|k|, cancelled on the Dirac branch whose gap is 2 arctan[qm/(1-qm)], while off-resonant spectators stay massless; media-mediated interaction obeys Ug = (1-2gq^2) U. Obstructions: ballistic transport admits only finite velocity sets; Abelian sign gauges leave the factorized surface; no protected 2-component node survives an exhaustive search. Finally, a dichotomy for the quaternionic event class: an isotropic cone forces overdamping -- Q = w_0/Gamma <= pi/(2 ln 2) at all densities, 0.66 at working density -- while in-state unitarity forces factorized transport. Postselected two-boundary amplitudes evade this, exactly unitary at all times under the fresh tape, with induced weight positivity open: the relativistic object here is an amplitude whose probabilistic reading is unsettled.

    hep-latquant-ph0 citations
  3. 03

    Chiral symmetry breaking for large "Nf" and the properties of the "rho" meson near the conformal window

    Aftab Ahmad🇵🇰 · Samreen Fatima🇵🇰 · Muhammad Shahbaz🇵🇰 · Marco Antonio Bedolla🇲🇽 · Alfredo Raya🇲🇽 · Muhammad Imran🇵🇰

    We study how the ground-state properties of the rho meson respond when the number of light-quark flavors N_f is driven towards the conformal window. The interaction is a symmetry-preserving, confining vector--vector contact interaction whose effective coupling carries a flavor dependence designed to encode the screening produced by fermion loops in the deep infrared. That interaction feeds the Schwinger--Dyson equation for the dressed-quark propagator and the homogeneous Bethe--Salpeter equation in the rainbow-ladder truncation, regularized in the Schwinger proper-time scheme so that quark production thresholds are absent while chiral symmetry remains broken. Raising N_f weakens the coupling, suppresses the dynamically generated mass and restores chiral symmetry together with deconfinement at a critical flavor number N^{c}_{f}. The vector channel responds differently from the pseudoscalar one. Because the is not a Goldstone boson, its mass is not protected by the symmetry that is being restored, and it simply follows the shrinking constituent scale, while the canonically normalized amplitude E_rho and the leptonic decay constant f_rho soften along the way. In this framework the rho sits above the nominal q\bar{q} threshold for every flavor number examined, so the state survives only as long as confinement removes that threshold. Dissociation is therefore governed by the divergence of the confinement length scale rather than by a crossing of the bound-state mass, and we contrast both criteria. The three elastic electromagnetic form factors G_E, G_M and G_Q, computed in the generalized impulse approximation, flatten as N_f grows, the zero crossing of G_E migrates towards the infrared and the charge radius expands, whereas the magnitude of the quadrupole moment decreases. The rho thus becomes a larger and rounder object as the theory approaches conformality.

    ↳ hep-phhep-exhep-lathep-th0 citations
  4. 04

    Precision Sum Rule for Nucleon Isovector Polarizabilities and the Proton-Neutron Mass Difference

    Xiong-Hui Cao🇨🇳 · Ling-Yun Dai🇨🇳 · Feng-Kun Guo🇨🇳

    The precision of the electromagnetic proton-neutron mass difference extracted from the Cottingham formula hinges on a subtraction function whose low-energy normalization is fixed by the isovector combination of the proton and neutron polarizabilities, . We derive a dispersive sum rule for this combination in terms of -channel photoabsorption cross sections and the product of -channel and amplitudes, without invoking Reggeon dominance. Combining empirical pion-photoproduction multipoles with coupled-channel Muskhelishvili--Omnès representations of the scalar-isovector amplitudes, we obtain , fixing its sign and reducing the uncertainty by a factor of 4 compared with the previously known value. This result yields , leading to , substantially more precise than previous Cottingham determinations. The negative also provides a stringent low-energy test of Reggeon dominance in the subtraction function.

    ↳ hep-phhep-latnucl-exnucl-th0 citations
  5. 05

    Determination of charged pion unpolarised TMDPDFs from Drell-Yan measurements

    Wen-Chen Chang🇹🇼 · Chia-Yu Hsieh🇹🇼 · Chung-Wen Kao🇹🇼 · C.-J. David Lin🇹🇼 · Valentin Moos🇹🇼 · Wayne Morris🇹🇼

    We present an extraction of the unpolarised transverse momentum dependent (TMD) parton distribution functions (PDFs) for the valence quarks in the pion from experimental mea- surements of the Drell-Yan process. The procedure adopted in this project relies on the framework of TMD factorisation, and the inputs of nucleon TMDPDF, pion collinear PDF, as well as the Collins-Soper kernel. The non-perturbative behaviour of the TMDPDFs is parameterised using an ansatz function that contains three unknown parameters and implements an exponential decay at large transverse distances. This work employs the most recent results in perturbation theory, and utilises a precise estimation of the nucleon TMDPDF. We perform an investigation of data used in the fit. This investigation leads to important observations regarding the effects of the kinematics and binning methods in the experimental data. Our results agree qualitatively with the previous determinations from phenomenology and a lattice computation

    ↳ hep-phhep-exhep-lat0 citations
  6. 06

    Comment for the SCAC Facilities Subcommittee from the Division of Particles and Fields of the American Physical Society

    D.S. Akerib🇺🇸 · A. De Gouvea🇺🇸 · P. Elmer🇺🇸 · S. Eno🇧🇯 · L. Fields🇺🇸 · A. Lankford · V. Martinez Outschoorn · P. Meade🇺🇸 · H. Murayama🇺🇸

    The Division of Particles and Fields (DPF) of the American Physical Society would like to thank SCAC for providing an opportunity for input to the SCAC facilities subpanel. The DPF represents scientists working at U.S. Universities and DOE Laboratories on understanding fundamental particles and forces. We are focused on Discovery Physics. The subpanel has been asked to consider two proposed DPF-related projects, the DUNE Phase II Detectors and supporting infrastructure and U.S. contributions to a future Higgs Factory. In this note, we briefly describe the questions driving our field and the P5 strategic plan and other community prioritization documents that form the backbone of our comment. The following sections provide short descriptions of the two projects, highlighting information relevant to your charge, answers to your specific questions, and a description of the process that produced this note.

    ↳ hep-exhep-lathep-phhep-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE