Nuclear Theory·nucl-th

Tuesday·April 8, 2025

20 papers—9 primary·11 cross-listed

10
Color superconductivity under neutron-star conditions at next-to-leading order
Andreas Geißel🇩🇪 · Tyler Gorda🇩🇪 · Jens Braun🇩🇪
The equation of state of deconfined strongly interacting matter at high densities remains an open question, with effects from quark pairing in the preferred color-flavor-locked (CFL) ground state possibly playing an important role. Recent studies suggest that at least large pairing gaps in the CFL phase are incompatible with current astrophysical observations of neutron stars. At the same time, it has recently been shown that in two-flavor quark matter, subleading corrections from pairing effects can be much larger than would be naïvely expected, even for comparatively small gaps. In the present Letter, we compute next-to-leading-order corrections to the pressure of quark matter in the CFL phase arising from the gap and the strong coupling constant, incorporating neutron-star equilibrium conditions and current state-of-the-art perturbative QCD results. We find that the corrections are again quite sizable, and they allow us to constrain the CFL gap in the quark energy spectrum to $Δ_{CFL} ≲ 140 MeV$ at a baryon chemical potential $μ_{B} = 2.6 GeV$ , even when allowing for a wide range of possible behaviors for the dependence of the gap on the chemical potential.
↳ hep-phnucl-thPRL(2025)·23 citations
11
Fragmentation functions for axial-vector heavy tetraquarks: A TQ4Q1.1 update
Francesco Giovanni Celiberto🇪🇸
We present and discuss the release of novel sets of collinear, variable-flavor-number-scheme fragmentation functions for axial-vector, fully heavy $T_{4 c} (1^{+-})$ and $T_{4 b} (1^{+-})$ tetraquarks. Working within the single-parton approximation at leading power and employing nonrelativistic QCD factorization adapted for tetraquark Fock states, we model the initial-scale fragmentation input using a recent calculation for the constituent heavy-quark channel. Standard DGLAP evolution is then applied, ensuring consistent implementation of evolution thresholds. To support phenomenology, we investigate NLL/NLO $^{+}$ rates for tetraquark-jet systems at the HL-LHC and FCC from (sym)JETHAD. This study further integrates exotic matter explorations with precision QCD calculations.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·18 citations
12
Nuclear Physics and the European Particle Physics Strategy Update 2026
L.M. Fraile🇪🇸 · J.J. Gaardhøje🇩🇰 · U. van Kolck🇮🇹 · H. Moutarde🇫🇷 · N. Patronis🇬🇷 · M.T. Peña🇵🇹 · L. Popescu🇧🇪 · V. Wagner🇨🇿 · E. Widmann (on behalf of NuPECC)🇦🇹
This document provides input to the update of the European Strategy for Particle Physics in fields that are related to Nuclear Physics as described in the NuPECC Long Range Plan 2024 (arXiv:2503.15575).
↳ nucl-exnucl-th0 citations
13
Study of nucleon and $Δ$ resonances from a systematic analysis of $K^{*} Σ$ photoproduction
Jun Shi🇨🇳 · Bing-Song Zou🇨🇳
A systematic analysis of the $K^{*} Σ$ photoproduction off proton is performed with all the available differential cross section data. We carry out a strategy different from the previous studies of these reactions, where, instead of fixing the parameters of the added resonances from PDG or pentaquark models, we add the resonance with a specific $J^{P}$ and leave its parameters to be determined from the experimental data. When adding only one resonance, the best result is to add one $N (3/ 2^{-})$ resonance around $2097$ MeV, which substantially reduces the $χ^{2}$ per degree of freedom to $1.35$ . There are two best solutions when adding two resonances, one is to add one $N^{*} (3/ 2^{-})$ and one $N^{*} (7/ 2^{-})$ , the other is to add one $N^{*} (3/ 2^{-})$ and one $Δ^{*} (7/ 2^{-})$ , leading the $χ^{2}$ per degree of freedom to be $1.10$ and $1.09$ , respectively. The mass values of the $N^{*} (3/ 2^{-})$ in the two resonance solutions are both near $2070$ MeV. Our solutions indicate that the $N (3/ 2^{-})$ resonance around $2080$ MeV is strongly coupled with the $K^{*} Σ$ final state and support the molecular picture of $N (2080, 3/ 2^{-})$ .
↳ hep-phnucl-thPRD(2025)·2 citations
14
Transverse-momentum-dependent pion structures from lattice QCD: Collins-Soper kernel, soft factor, TMDWF, and TMDPDF
Dennis Bollweg🇺🇸 · Xiang Gao🇺🇸 · Jinchen He🇺🇸 · Swagato Mukherjee🇺🇸 · Yong Zhao🇺🇸
We present the first lattice quantum chromodynamics (QCD) calculation of the pion valence-quark transverse-momentum-dependent parton distribution function (TMDPDF) within the framework of large-momentum effective theory (LaMET). Using correlators fixed in the Coulomb gauge (CG), we computed the quasi-TMD beam function for a pion with a mass of 300 MeV, a fine lattice spacing of $a = 0.06$ fm and multiple large momenta up to 3 GeV. The intrinsic soft functions in the CG approach are extracted from form factors with large momentum transfer, and as a byproduct, we also obtain the corresponding Collins-Soper (CS) kernel. Our determinations of both the soft function and the CS kernel agree with perturbation theory at small transverse separations ( $b_{⊥}$ ) between the quarks. At larger $b_{⊥}$ , the CS kernel remains consistent with recent results obtained using both CG and gauge-invariant TMD correlators in the literature. By combining next-to-leading logarithmic (NLL) factorization of the quasi-TMD beam function and the soft function, we obtain $x$ -dependent pion valence-quark TMDPDF for transverse separations $b_{⊥} ≳ 1$ fm. Interestingly, we find that the $b_{⊥}$ dependence of the phenomenological parameterizations of TMDPDF for moderate values of $x$ are in reasonable agreement with our QCD determinations. In addition, we present results for the transverse-momentum-dependent wave function (TMDWF) for a heavier pion with 670 MeV mass.
↳ hep-lathep-exhep-phnucl-ex+1PRD(2025)·33 citations
15
Perturbation theory of rotating scalar fields and vacuum insensitivity to rotation
Ryo Kuboniwa🇯🇵 · Kazuya Mameda🇯🇵
We formulate the finite-temperature perturbation theory of interacting scalar fields under external rotation. Because of the translational non-invariance in the radial direction, Green's functions are described using the Fourier-Bessel basis, instead of the conventional Fourier basis. We derive the leading-order correction to the partition function and the one-loop self-energy. The Feynman rules obtained in our perturbation theory shows that due to the finite-size effect required by the causality constraint, the zero-temperature thermodynamics in the perturbation theory is unaffected by rotation, similarly to that in the noninteracting theory.
↳ hep-thhep-phnucl-thPLB(2026)·7 citations
16
Charmonium-nucleon femtoscopic correlation function
Zhi-Wei Liu🇨🇳 · Duo-Lun Ge🇨🇳 · Jun-Xu Lu🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳
This study investigates the femtoscopic correlation functions of charmonium-nucleon pairs, utilizing the lattice QCD phase shifts provided by the HAL QCD Collaboration. A ``model-independent'' formalism is employed to transform scattering phase shifts directly into momentum correlation functions, thereby circumventing the approximations inherent in traditional methods, such as the Lednický-Lyuboshits model. The $J / ψ$ - $p$ correlation functions, including spin-averaged and partial-wave results, are predicted using near-physical pion mass lattice results. The $η_{c}$ - $p$ correlation function is calculated for the first time. The derived correlation functions provide critical references for future experiments, such as those at the LHC, where high-precision measurements of charmonium-nucleon correlations could unveil valuable insights into non-perturbative QCD dynamics.
↳ hep-phnucl-thPRD(2025)·16 citations
17
Investigation of the baryon time-like electromagnetic form factors in the electron-positron annihilation reactions
Ju-Jun Xie · Cheng Chen
Based on the experimental measurements of the electron-positron annihilation reactions into a baryon ( $B$ ) and anti-baryon ( $B ˉ$ ) pair, the electromagnetic form factors of hyperons in the time-like region can be investigated within the vector meson dominance model. The theoretical model parameters are determined by fitting them to the total cross sections of the process $e^{+} e^{-} \to B B ˉ$ , and it is found that the current experimental data on the baryon electromagnetic form factors in the time-like region can be well reproduced. In addition to the total cross sections, the electromagnetic form factors $G_{E}$ and $G_{M}$ , and the charge radii of those baryons are also estimated, which are in agreement with the experimental data. On the other hand, we have also investigated the nonmonotonic behavior of the time-like baryon electromagnetic form factors, and it is found that the previously proposed periodic behaviour of the nucleon time-like electromagnetic form factor is not confirmed. However, we do observe the nonmonotonic structures in the line shape of the baryon effective form factors or the ratio $∣ G_{E} / G_{M} ∣$ for the charmed baryon $Λ_{c}^{+}$ . These features can be naturally explained by incorporating contributions from excited vector states. More precise measurements of the $e^{+} e^{-} \to B B ˉ$ reaction offer a valuable opportunity to probe the properties of excited vector states, which are at present poorly known. Additionally, comprehensive theoretical and experimental studies of baryon timelike electromagnetic form factors can provide critical insights into the underlying mechanisms of electron-positron annihilation processes.
↳ hep-phhep-exnucl-exnucl-thPoS(2025)·0 citations
18
Finite density signatures of confining and chiral dynamics in QCD thermodynamics and fluctuations of conserved charges
Yi Lu🇨🇳 · Fei Gao🇨🇳 · Yu-xin Liu🇨🇳 · Jan M. Pawlowski🇩🇪
We evaluate thermodynamic observables such as pressure, baryon number, entropy and energy density, as well as the second and fourth order baryon number cumulants in the phase structure of QCD. The intertwined confinement and chiral dynamics is resolved within functional QCD, aiming for quantitative accuracy at larger densities. Specifically it is shown that the self-consistent resolution of the confining gluonic background is crucial in particular for even the qualitative properties of the cumulants. Our results are in quantitative agreement with lattice and functional QCD benchmarks at vanishing and small chemical potentials. Moreover, they offer novel insights in the dynamics at larger chemical potentials including the regime of the critical end point. A welcome by-product of this analysis is the computation of the Polyakov loop potential in finite density QCD, which, alongside the aforementioned observables, can be used as input and benchmark for effective theory computations at finite density.
↳ hep-phhep-thnucl-exnucl-thPRD(2026)·31 citations
19
One-loop transverse-momentum-dependent soft function at higher orders in the dimensional regulator
Hua-Sheng Shao🇫🇷 · Guoxing Wang🇫🇷
The transverse-momentum-dependent (TMD) soft function for a generic hadroproduction process involving massive colored particles is analytically calculated at the one-loop level, extended to higher orders in the dimensional regulator $ϵ$ . We present both the azimuthal-angle-averaged and azimuthal-angle-dependent soft functions in impact-parameter space, making them suitable for small $q_{T}$ resummation calculations. Their analytic expressions are provided in terms of multiple polylogarithms. Our results offer essential ingredients for a complete higher-order perturbative calculation of the TMD soft function.
↳ hep-phnucl-thJHEP(2025)·6 citations
20
Precision DIS thrust predictions for HERA and EIC
June-Haak Ee🇺🇸 · Daekyoung Kang🇨🇳 · Christopher Lee🇺🇸 · Iain W. Stewart🇺🇸
We present predictions for the DIS 1-jettiness event shape $τ_{1}^{b}$ , or DIS thrust, using the framework of Soft Collinear Effective Theory (SCET) for factorization, resummation of large logarithms, and rigorous treatment of nonperturbative power corrections, matched to fixed-order QCD away from the resummation region. Our predictions reach next-to-next-to-next-to-leading-logarithmic (N $^{3}$ LL) accuracy in resummed perturbation theory, matched to $O (α_{s}^{2})$ fixed-order QCD calculations obtained using the program NLOJet++. We include a rigorous treatment of hadronization corrections, which are universal across different event shapes and kinematic variables $x$ and $Q$ at leading power, and supplement them with a systematic scheme to remove $O (Λ_{QCD})$ renormalon ambiguities in their definition. The framework of SCET allows us to connect smoothly the nonperturbative, resummation, and fixed-order regions, whose relative importance varies with $x$ and $Q$ , and to rigorously estimate theoretical uncertainties, across a broad range of $x$ and $Q$ covering existing experimental results from HERA as well as expected new measurements from the upcoming Electron-Ion-Collider (EIC). Our predictions will serve as an important benchmark for the EIC program, enabling the precise determination of the QCD strong coupling $α_{s}$ and the universal nonperturbative first moment parameter $Ω_{1}$ .
↳ hep-phnucl-thJHEP(2025)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE