Nuclear Theory·nucl-th

Monday·June 10, 2024

7 papers—2 primary·5 cross-listed

03
Proton 3D reconstruction with T-odd TMD gluon densities
Alessandro Bacchetta🇮🇹 · Francesco Giovanni Celiberto🇪🇸 · Marco Radici🇮🇹
We present studies aimed at probing the 3D gluon content of the proton through spin-dependent TMD gluon densities, computed by means of the spectator-model approach. Our formalism incorporates a fit-based modulation function for the spectator mass, designed to capture longitudinal-momentum effects across a broad kinematic range. Special emphasis is placed on the time-reversal even Boer-Mulders and the time-reversal odd Sivers functions. Accurate understanding of these functions is crucial for conducting precise 3D analyses of nucleons, highlighting the importance of collaborative efforts between the LHC and EIC Communities.
↳ hep-phhep-exnucl-exnucl-thPoS(2024)·8 citations
04
Deconfinement and chiral phase transitions in quark matter with chiral imbalance
Francisco X. Azeredo🇧🇷 · Dyana C. Duarte🇧🇷 · Ricardo L. S. Farias🇧🇷 · Gastão Krein🇧🇷 · Rudnei O. Ramos🇧🇷
We study the thermodynamics of the Polyakov-Nambu-Jona-Lasinio model considering the effects of an effective chiral chemical potential. We offer a new parametrization of the Polyakov-loop potential depending on temperature and the chiral chemical potential which, when used together with a proper regularization scheme of vacuum contributions, predicts results consistent with those from lattice simulations.
↳ hep-phhep-lathep-thnucl-thPRD(2024)·16 citations
05
Shear viscosity from perturbative Quantum Chromodynamics to the hadron resonance gas at finite baryon, strangeness, and electric charge densities
Isabella Danhoni🇩🇪 · Jordi Salinas San Martin🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸
Through model-to-data comparisons from heavy-ion collisions, it has been shown that the Quark Gluon Plasma has an extremely small shear viscosity at vanishing densities. At large baryon densities, significantly less is known about the nature of the shear viscosity from Quantum Chromodynamics (QCD). Within heavy-ion collisions, there are three conserved charges: baryon number (B), strangeness (S), and electric charge (Q). Here we calculate the shear viscosity in two limits using perturbative QCD and an excluded-volume hadron resonance gas at finite BSQ densities. We then develop a framework that interpolates between these two limits such that shear viscosity is possible to calculate across a wide range of finite BSQ densities. We find that the pQCD and hadron resonance gas calculations have different BSQ densities dependence such that a rather non-trivial shear viscosity appears at finite densities.
↳ hep-phnucl-thPRD(2025)·8 citations
06
Wave functions of multiquark hadrons from representations of the symmetry groups $S_{n}$
Nicholas Miesch🇺🇸 · Edward Shuryak🇺🇸
Construction of the wave functions of multiquark hadrons by traditional method based on tensor products of colors, flavors, spins (and orbital) parts becomes quite complex when quark numbers grow $n = 5, 6...12$ , as it gets difficult to satisfy requirements of Fermi statistics. Our novel approach is focused directly on representations of the permutation symmetry generators. After showing how $C_{3}$ is manifested in the wave functions of (excited) baryons, we use it to construct the wave functions for a set of pentaquarks and hexaquarks (n=5,6). We also have some partial results for larger systems, with $n = 9$ and 12, and even beyond that as far as $n = 24$ .
↳ hep-phnucl-thPRD(2024)·5 citations
07
Unraveling Trace Anomaly of Supradense Matter via Neutron Star Compactness Scaling
Bao-Jun Cai · Bao-An Li
The trace anomaly $Δ \equiv 1/3 - P / ε = 1/3 - ϕ$ quantifies the possibly broken conformal symmetry in supradense matter under pressure $P$ at energy density $ε$ . Perturbative QCD (pQCD) predicts a vanishing $Δ$ at extremely high energy or baryon densities when the conformal symmetry is realized but its behavior at intermediate densities reachable in neutron stars (NSs) are still very uncertain. The extraction of $Δ$ from NS observations strongly depends on the employed model for nuclear Equation of State (EOS). Using the IPAD-TOV method based on an Intrinsic and Perturbatively Analysis of the Dimensionless (IPAD) Tolman-Oppenheimer-Volkoff (TOV) equations that are further verified numerically by using $1 0^{5}$ EOSs generated randomly with a meta-model in a very broad EOS parameter space constrained by terrestrial nuclear experiments and astrophysical observations, here we first show that the compactness $ξ \equiv G M_{NS} / R c^{2} \equiv M_{NS} / R$ of a NS with mass $M_{NS}$ and radius $R$ scales very accurately with $Π_{c} \equiv Π_{c} \cdot (1 + 18 \x /25) \equiv \x / (1 + 3 \x^{2} + 4 \x) \cdot (1 + 18 X /25)$ where $\x \equiv ϕ_{c} = P_{c} / ε_{c}$ is the ratio of pressure over energy density at NS centers. The scaling of NS compactness thus enables one to readily read off the central trace anomaly $Δ_{c} = 1/3 - \x$ directly from the observational data of either the mass-radius or red-shift measurements. We then demonstrate indeed that the available NS data themselves from recent X-ray and gravitational wave observations can determine model-insensitively the trace anomaly as a function of energy density in NS cores, providing a stringent test of existing NS models and a clear guidance in a new direction for further understanding the nature and EOS of supradense matter.
↳ astro-ph.HEhep-phhep-thnucl-ex+1PRD(2025)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE

Proton 3D reconstruction with T-odd TMD gluon densities

Deconfinement and chiral phase transitions in quark matter with chiral imbalance

Shear viscosity from perturbative Quantum Chromodynamics to the hadron resonance gas at finite baryon, strangeness, and electric charge densities

Wave functions of multiquark hadrons from representations of the symmetry groups Sn​

Unraveling Trace Anomaly of Supradense Matter via Neutron Star Compactness Scaling

Affiliations

Wave functions of multiquark hadrons from representations of the symmetry groups $S_{n}$