HEP Lattice·hep-lat

Mon·Jul 27, 2026Monday·July 27, 2026

5 papers—3 primary·2 cross-listed

01
Lattice study of spin interactions between heavy quarks in the quark-gluon plasma
Dibyendu Bala🇩🇪 · Olaf Kaczmarek🇩🇪 · Sayantan Sharma🇮🇳 · Swagatam Tah🇮🇳
We calculate the spin-dependent potential, which is the $O (1/ M^{2})$ correction term to the thermal potential between a static quark-antiquark pair within non-relativistic QCD. At leading order in hard thermal loop perturbation theory, we show that this spin-dependent potential has an imaginary part which is different in magnitude for pseudoscalar and vector quarkonium states. For the first time, we extract the imaginary part non-perturbatively using lattice techniques, in the deconfined phase of quenched QCD at $T \sim 470$ MeV, after performing a continuum estimation and subsequent renormalization. We have found that the spin-dependent potential in the quark-gluon plasma phase is complex, and its imaginary part has a remarkably significant contribution over the thermal static potential for charmonium states. Consequences of this thermal spin-dependent potential on the quarkonium spectral functions are also discussed.
hep-lathep-phnucl-exnucl-th0 citations
02
Resonances at finite temperature from the lattice
Jakob Hoffmann🇩🇪 · Peter Lowdon🇩🇪 · Owe Philipsen🇩🇪
The properties of hadronic resonances at finite temperature constitute an important probe of the thermal QCD medium. In this work we use the concept of thermoparticles, which characterise thermally-modified but stable particle-like states, to define the notion of two-particle scattering at finite temperature, and establish a unitarity relation for the thermal scattering amplitude. We derive a finite-temperature generalisation of the vacuum two-particle quantisation condition via a skeleton expansion of the finite-volume correlation function. Solving this condition at the finite-volume energy levels of the system constrains the form of the thermal scattering amplitude, and hence the properties of resonances. In contrast to the vacuum case, the kinematic function containing the leading finite-volume corrections is finite at all energies, reflecting the fact that thermoparticles have broadened spectral peaks due to their interactions with the thermal medium. Since all lattice simulations involve a finite temporal extent, our approach can also be used to study finite-temporal size effects in vacuum analyses.
hep-lathep-phhep-thnucl-th0 citations
03
First Lattice QCD Determination of Lepton-Flavor-Universality Ratios in Light-Meson Leptonic Decays
Peter Boyle🇺🇸 · Norman H. Christ🇺🇸 · Xu Feng🇨🇳 · Taku Izubuchi🇺🇸 · Luchang Jin🇺🇸 · Christopher T. Sachrajda🇬🇧 · Xin-Yu Tuo🇺🇸
The ratio of electronic to muonic leptonic decay widths, $R_{e / μ}$ , for the light mesons $π$ and $K$ , provides a clean test of lepton flavor universality (LFU) and a sensitive probe of physics beyond the Standard Model. Its Standard-Model prediction is exceptionally precise, with the leading uncertainty associated with the structure-dependent (SD) radiative correction of $O (0.1%)$ . As experiments such as PIONEER and NA62 aim for unprecedented precision, this SD correction has become an essential ingredient in precision experiment--theory comparisons. We present the first lattice QCD $+$ QED calculation of this SD correction at the physical pion mass and in the continuum limit. We employ the infinite-volume reconstruction (IVR) method with Coulomb-gauge photons, significantly reducing both statistical errors and finite-volume effects. We obtain the Standard-Model predictions, $R_{e / μ} = 1.23501 (10) \times 1 0^{- 4}$ for $π$ and $R_{e / μ} = 2.47653 (34) \times 1 0^{- 5}$ for $K$ . Our results reduce the hadronic uncertainty in $R_{e / μ}$ , provide the most precise Standard-Model predictions to date, and establish first-principles benchmarks for future high-precision tests of LFU.
hep-lathep-ph1 citation
04
Revisiting Quark Confinement in the Proton through the Force on Quarks
Ji-Xin Yu🇨🇳 · Ao-Sheng Xiong🇨🇳 · Ji Xu🇨🇳 · Fu-Sheng Yu🇨🇳 · Yong Zheng🇨🇳
Quark confinement, the fact that colored quarks are permanently bound inside color-neutral hadrons and have never been observed as isolated particles, remains one of the central issues of the Standard Model. Recently, Ji et al.\,\cite{Ji:2026lyj} proposed a framework to define and measure the force on quarks in the proton, obtaining strong evidence for a net confining force and thus opening a new perspective on the study of confinement. In this work, we improve this analysis by incorporating light-cone QCD sum rule results to supplement the limited experimental and lattice QCD information in the large- $∣ q^{2} ∣$ region. We further formulate the reconstruction of the quark force as a regularized inverse problem, thereby reducing the model dependence associated with the prescribed functional parametrizations used before. The resulting quark force provides a complementary, less parametrization-dependent determination and remains consistent with that implied by a linear QCD potential, which also supports the robustness of the framework proposed in Ref.\,\cite{Ji:2026lyj}. We also show that improved future inputs can substantially reduce the uncertainty in the reconstructed quark force.
↳ hep-phhep-exhep-latnucl-ex0 citations
05
Hot and Dense Medium Effects on the $B_{s}^{*}$ and $B^{*}$ Multiplets
K. Azizi🇮🇷 · N. Er🇹🇷 · J.Y. Süngü🇹🇷
We present an extensive analysis of the in-medium masses and decay constants of the $B_{s}^{*} (5415)$ and $B^{*} (5325)$ multiplets, including both particles and antiparticles, using QCD sum rules at finite temperature and density. The OPE incorporates the full temperature- and density-dependent contributions from the quark, gluon, and mixed condensates. Computing the strange ( $B_{s}^{* 0}$ , $B ˉ_{s}^{* 0}$ ), charged ( $B^{*\pm}$ ), and neutral ( $B^{* 0}$ , $B ˉ^{* 0}$ ) doublet properties allows us to study the effects of flavor symmetry breaking, strangeness, and heavy-quark decoupling on the beauty vector mesons in the medium. Our results indicate that the mass is remarkably resistant to the medium across the entire multiplet: no state loses more than $\sim 13%$ of its vacuum value, even at $T = T_{c}$ and $n = 5 n_{0}$ , the extreme conditions explored here. The decay constant is far more sensitive, losing up to $\sim 78%$ at the same point. Baryon density clearly dominates the medium response, while temperature plays a secondary role until the system approaches the deconfinement crossover. At zero density, every state loses almost the same fraction of its mass and decay constant: mass shifts lie between $- (0.5$ - $1.1) %$ and decay-constant shifts between $- (3.9$ - $5.3) %$ , regardless of charge or flavor, so temperature alone does not distinguish a particle from its antiparticle. At finite baryon density, a clear particle-antiparticle asymmetry emerges: at $T = 0$ and $n = 5 n_{0}$ , the $B ˉ^{* 0}$ mass decreases by $12.9%$ , whereas the $B^{* 0}$ mass shifts by only $6.1%$ , a gap of nearly seven percentage points driven entirely by the vector self-energy. This provides a theoretical basis for the future heavy-ion collision program at RHIC, LHC, FAIR, and NICA.
↳ hep-phhep-exhep-lat1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Lattice study of spin interactions between heavy quarks in the quark-gluon plasma

Resonances at finite temperature from the lattice

First Lattice QCD Determination of Lepton-Flavor-Universality Ratios in Light-Meson Leptonic Decays

Revisiting Quark Confinement in the Proton through the Force on Quarks

Hot and Dense Medium Effects on the Bs∗​ and B∗ Multiplets

Affiliations

Hot and Dense Medium Effects on the $B_{s}^{}$ and $B^{}$ Multiplets