Nuclear Theory·nucl-th

Monday·December 23, 2024

10 papers—2 primary·8 cross-listed

01
Quark-Quark and Quark-nucleon Potential model Extended-soft-core meson-exchange Interactions
Th. A. Rijken🇳🇱 · Y. Yamamoto🇯🇵
The Quark-quark (QQ) and Quark-nucleon (QN) interactions in this paper are derived from the Extended-soft-core (ESC) interactions. The meson-quark-quark (MQQ) vertices are determined in the framework of the constituent quark model (CQM). These vertices are such that upon folding with the ground-state baryon quark wave functions the one-boson-exchange (OBE) amplitudes for baryon-baryon (BB), and in particularly for nucleon-nucleon (NN), are reproduced. This opens the attractive possibility to define meson-quark interactions at the quark level which are directly related related to the interactions at the baryon level. the latter have been determined by the baryon-baryon data. Application of these "realistic" quark-quark interactions in the quark-matter phase is presumably of relevance for the description of highly condensed matter, as e.g. neutron-star matter.
nucl-thhep-ph2 citations
02
Constraining neutron star properties through parity-violating electron scattering experiments and relativistic point coupling interactions
P.S. Koliogiannis🇭🇷 · E. Yuksel🇬🇧 · N. Paar🇭🇷
Parity-violating electron scattering experiments on $^{48} Ca$ (CREX) and $^{208} Pb$ (PREX-2) offer valuable insight into the isovector properties of finite nuclei, providing constraints for the density dependence of the nuclear equation of state, which is crucial for understanding astrophysical phenomena. In this work, we establish functional dependencies between the properties of finite nuclei-such as weak charge form factors and neutron skin thickness-and the bulk properties of neutron stars, including tidal deformability from binary neutron star mergers and neutron star radii. The dependencies are formulated by introducing a family of $β$ -equilibrated equations of state based on relativistic energy density functionals with point coupling interactions. The charge minus the weak form factors derived from CREX and PREX-2 measurements, combined with the observational constraints on tidal deformability from the GW170817 event, are used to constrain the symmetry energy and neutron star radii. Notably, the energy density expanded up to the fourth order in symmetry energy yields larger radii compared to calculations limited to the second order term. However, the results reveal a discrepancy between the constraints provided by the CREX and PREX-2 experiments. For a more quantitative assessment, higher precision parity-violating electron scattering data and neutron star observations are required.
nucl-thastro-ph.HEastro-ph.SRnucl-exPLB(2025)·5 citations
03
Baryon Form Factors
Yong-Hui Lin🇩🇪 · Hans-Werner Hammer🇩🇪 · Ulf-G. Meißner🇩🇪
We review the status of baryon form factors with a special focus on the nucleon electromagnetic form factors which are known best. First, we give an introduction into the dispersive analyses and emphasize the role of unitarity and analyticity in the construction of the isoscalar and isovector spectral functions. Second, we present the state of the art in our understanding of nucleon form factors and radii including reliable uncertainty estimates from bootstrap and Bayesian methods. Third, we discuss the physics of the time-like form factors and point out further issues to be addressed in this framework. Finally, we review the status of hyperon form factors and comment on the pion cloud.
↳ hep-phnucl-thEncyclopedia of Particle Physics(2024)·5 citations
04
Global parametrizations of $π π$ scattering with dispersive constraints: Beyond the S0 wave
J. R. Peláez🇪🇸 · P. Rabán🇪🇸 · J. Ruiz de Elvira🇪🇸
We provide new global parametrizations of $π π \to π π$ scattering for the S2, P, D, F, and G partial waves up to at least 1.8 GeV, easy to implement for phenomenological use. With earlier S0-wave parametrizations, slightly updated here, they reproduce previous partial wave dispersion analyses up to the $π ω$ threshold. In addition, these new parametrizations have improved their description of recent P-wave data, the inelasticity in various waves, and their fulfillment of Roy-like and forward dispersion relations. The latter now test very high partial waves and have an improved matching with the Regge regime, extending those with P-wave contributions up to 1.6 GeV. Above 1.6 GeV and up to 1.8 GeV, or sometimes somewhat beyond, the parametrizations are simple unconstrained fits to data.
↳ hep-phhep-exhep-latnucl-thPRD(2025)·24 citations
05
Correlations of net baryon number and electric charge in nuclear matter
Xin-ran Yang🇨🇳 · Guo-yun Shao🇨🇳 · Chong-long Xie🇨🇳 · Zhi-Peng Li🇨🇳
We investigate the correlations between net baryon number and electric charge up to sixth order related to the interactions of nuclear matter at low temperature, and explore their relationship with the nuclear liquid-gas phase transition (LGPT) within the framework of the nonlinear Walecka model. The calculation shows that strong correlations between the baryon number and electric charge exist in the vicinity of LGPT, and the higher order correlations are more sensitive than the lower order ones near the phase transition. However, in the high-temperature region away from the LGPT the rescaled lower order correlations are relatively larger than most of the higher order ones. Besides, some of the fifth- and sixth-order correlations possibly change the sign from negative to positive along the chemical freeze-out line with the decrease of temperature. In combination with the future experimental projects at lower collision energies, the derived results can be referred to study the phase structure of strongly interacting matter and analyze the related experimental signals.
↳ hep-phnucl-thNucl.Sci.Tech.(2025)·5 citations
06
Dense QC $_{2}$ D. What's up with that?!?
Simon Hands🇬🇧 · Seyong Kim🇰🇷 · Dale Lawlor🇮🇪 · Andrew Lee-Mitchell🇮🇪 · Jon-Ivar Skullerud🇮🇪
We present recent updates and results from QC $_{2}$ D (Two Colour QCD) simulations at non-zero baryon density, including progress toward determining the speed of sound.
↳ hep-lathep-phnucl-thPoS(2025)·9 citations
07
The QCD moat regime and its real-time properties
Wei-jie Fu🇨🇳 · Jan M. Pawlowski🇩🇪 · Robert D. Pisarski🇺🇸 · Fabian Rennecke🇩🇪 · Rui Wen🇨🇳 · Shi Yin🇩🇪
Dense QCD matter may exhibit crystalline phases. Their existence is reflected in a moat regime, where mesonic correlations feature spatial modulations. We study the realtime properties of pions at finite temperature and density in QCD in order to elucidate the nature of this regime. We show that the moat regime arises from particle-hole-like fluctuations near the Fermi surface. This gives rise to a characteristic peak in the spectral function of the pion at nonzero \emph{spacelike} momentum. This peak can be interpreted as a new quasi particle, the moaton. In addition, our framework also allows us to directly test the stability of the homogeneous chiral phase against the formation of an inhomogeneous condensate in QCD. We find that the formation of such a phase is highly unlikely for baryon chemical potentials $μ_{B} \leq 630$ \,MeV.
↳ hep-phhep-thnucl-thPRD(2025)·41 citations
08
Heavy-quark mass effects in off-light-cone distributions
Valerio Bertone🇫🇷 · Michael Fucilla🇫🇷 · Cédric Mezrag🇫🇷
We compute the one-loop correction to the forward matrix element of an off-light-cone bi-local quark correlator characterised by a space-like separation $z^{2}$ in the presence of heavy quarks with mass $m$ . This calculation allows us to extract the one-loop matching kernel, necessary to connect quasi and pseudo-distributions to collinear parton distribution functions (PDFs), accounting for heavy-quark mass effects. Our result is exact in that it includes all powers of $z^{2} m^{2}$ at one loop in $α_{s}$ . In the limit $z^{2} m^{2} \to 0$ , it consistently reduces to the known massless result. We also carry out an implementation of our expression, which allows us to compute the charm pseudo-distribution of the proton given its PDF. We finally comment on the quantitative impact of heavy-quark mass corrections.
↳ hep-phhep-latnucl-thEPJC(2025)·0 citations
09
Functional renormalization of QCD in $1 + 1$ dimensions: four-fermion interactions from quark-gluon dynamics
Eric Oevermann🇩🇪 · Adrian Koenigstein🇩🇪 · Stefan Floerchinger🇩🇪
Quantum Chromodynamics in two spacetime dimensions is investigated with the Functional Renormalization Group. We use a functional formulation with covariant gauge fixing and derive Renormalization Group flow equations for the gauge coupling, quark mass and an algebraically complete set of local fermion-fermion interaction vertices. The flow, based on a convenient Callan-Symanzik-type regularization, shows the expected behavior for a super-renormalizable theory in the ultraviolet regime and leads to a strongly coupled regime in the infrared. Through a detailed discussion of symmetry implications, and variations in the gauge group and flavor numbers, the analysis sets the stage for a more detailed investigation of the bound state spectrum in future work.
↳ hep-phhep-thnucl-thPRD(2025)·5 citations
10
Phase structure of quark matter and in-medium properties of mesons from Callan-Symanzik flows
Sebastian Töpfel🇩🇪 · Jan M. Pawlowski🇩🇪 · Jens Braun🇩🇪
We compute meson spectral functions at finite temperature and density in the quark-meson model, supplemented with a computation of the phase diagram. In particular, we provide a detailed analysis of the non-analytic structure of the meson two-point functions which is of great relevance for phenomenological applications, such as moat regimes and inhomogeneous phases. Furthermore, it is also relevant from a field-theoretical standpoint as it provides an insight into the applicability of derivative expansions of the effective action to studies of general fermion-boson models, both at zero and finite chemical potential. Our computation is based on a functional renormalization group setup that preserves causality, all spacetime symmetries, and the Silver-Blaze property. The combination of these properties can only be achieved by a Callan-Symanzik regulator. Instead of momentum shell integrations, renormalization group flows generated by such a regulator describe the change of the theory induced by a change of the masses of the mesons and quarks. A particular focus of our work lies on the construction of controlled Callan-Symanzik flows in the presence of spontaneous and explicit chiral symmetry breaking by means of chiral Ward-Takahashi identities.
↳ hep-phnucl-thPRD(2026)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE