Nuclear Theory·nucl-th

Tuesday·April 29, 2025

14 papers—10 primary·4 cross-listed

11
[Submitted on 26 Apr 2025] (cross-list from hep-ph)
Moat regimes within a $2 + 1$ flavor Polyakov-quark-meson model
Gaoqing Cao🇨🇳
To better understand recent predictions on the moat regime of quantum chromodynamics (QCD) matter, this paper extends the previous work within the two-flavor quark-meson (QM) model to the more realistic $2 + 1$ flavor Polyakov-quark-meson (PQM) model. Mainly, two effects are further taken into account: strange quark and confinement coded through Polyakov loop. Model parameters are chosen to consistently reproduce the pseudocritical temperature from lattice QCD, $T_{C} \sim 156 MeV$ , and the baryon chemical potential at the critical end point (CEP) from FRG-QCD, $μ_{B (CEP)} \sim 635 MeV$ . It is found that the basic features of moat regimes for $σ$ and $π$ mesons remain similar to those from QM model: Moat regimes cover the region where temperature or baryon chemical potential is large; reentrances occur around the critical baryon chemical potential of chiral transition at zero temperature. Thus, the FRG-QCD results can still not be well understood, especially why the CEP should locate at the entrances of moat regimes for $σ$ and $π$ mesons. Nevertheless, some basic features can be understood qualitatively, and it is consistent that the pole energies are increasing functions of momenta in the whole $T - μ_{B}$ plane. The moat regime and pole energy of $K$ mesons are also studied with the features similar.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2504.18874 [pdf]
PRD(2025)·7 citations
12
[Submitted on 28 Apr 2025] (cross-list from hep-ph)
Different scenarios of dynamical chiral symmetry breaking in the interacting instanton liquid model via flavor symmetry breaking
Yamato Suda🇯🇵 · Daisuke Jido🇯🇵
We investigate a type of dynamical chiral symmetry breaking (D $χ$ SB) for various current quark masses using the interacting instanton liquid model. The type of D $χ$ SB is classified based on the sign of the second derivative of the free energy density with respect to the quark condensate at the origin. We perform numerical simulations of the interacting instanton liquid model with the flavor SU(2) symmetric and (2+1)-flavor quarks. We find that the curvature is negative in the SU(2) case. This means the ordinary type of D $χ$ SB. In contrast, in the (2+1)-flavor case, a positive curvature is observed when the strange quark mass is as small as those of the up and down quarks. This suggests that the anomaly-driven type of D $χ$ SB can occur under the approximate flavor SU(3) symmetry. As the strange quark mass increases, the curvature gradually decreases and becomes negative when the strange quark mass is approximately three times larger than those of the light quarks. This difference can be understood in terms of the 't Hooft vertex which induces a six-quark interaction in the $N_{f} = 3$ case and does a four-quark interaction in the $N_{f} = 2$ case. Our results might indicate that the ratio between the strange and light quark masses plays a crucial role in understanding the microscopic relationship between D $χ$ SB and the anomaly effect.
Comments:
11 pages, 8 figures, 2 tables; some discussion have added and clarified; minor corrections have added
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2504.19469 [pdf]
PRD(2025)·1 citation
13
[Submitted on 28 Apr 2025] (cross-list from hep-ph)
Properties of $X (3872)$ from hadronic potentials coupled to quarks
Ibuki Terashima · Tetsuo Hyodo
The concept of compositeness is used to quantitatively discuss the hadronic molecular nature in exotic hadrons. In this work, we develop a formulation to explicitly introduce the compact quark state contribution in the hadronic potentials together with the direct four-point interaction. We derive analytic expressions of the compositeness from the effective potential between hadrons when the system has a bound state. Applying this formulation to the $X (3872)$ , we examine the variation of the compositeness with respect to the binding energy, energy of $χ_{c 1} (2 P)$ , cutoff momentum, and strength of the direct $D^{0} D ˉ^{* 0}$ interaction.
Comments:
8 pages, 4 figures, proceedings of The XVIth Quark Confinement and the Hadron Spectrum Conference (QCHSC24), August 19th-24th, 2024
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2504.19471 [pdf]
PoS(2025)·0 citations
14
[Submitted on 28 Apr 2025] (cross-list from physics.atom-ph)
$^{208}$ Pb nuclear charge radius revisited: closing the fine-structure-anomaly gap
Zewen Sun · Konstantin Beyer · Zoia A. Mandrykina · Igor A. Valuev · Christoph H. Keitel · Natalia S. Oreshkina
A comprehensive reevaluation of the root-mean-square nuclear charge radius is presented for the doubly magic $^{208}$ Pb extracted from muonic spectroscopy measurements. By integrating rigorous theoretical quantum electrodynamics calculations, state-of-the-art numerical methods, and a systematic reanalysis of the uncertainties, we reduced the long-standing muonic fine-structure anomaly and improved the goodness of fit by a factor of twenty. The resulting value of 5.5062(5)~fm for a Fermi distribution is fairly consistent with the previously reported muonic spectroscopy value, and three standard deviations larger than the commonly used compilation data, which indicates that the current value and its uncertainty could be significantly underestimated. Attributing the remaining discrepancy to theory errors which can not be rigorously calculated we suggest the rms charge radius with reduced model dependence to be 5.5062(17) fm. This work sets an improved benchmark for charge radius extraction in heavy nuclei and paves a path for systematic reevaluations across the nuclear chart.
Comments:
11 pages, 4 figures
Subjects:
Atomic Physics (physics.atom-ph); Nuclear Theory (nucl-th)
arXiv:
2504.19977 [pdf]
PRL(2025)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE

Moat regimes within a 2+1 flavor Polyakov-quark-meson model

Different scenarios of dynamical chiral symmetry breaking in the interacting instanton liquid model via flavor symmetry breaking

Properties of X(3872) from hadronic potentials coupled to quarks

208Pb nuclear charge radius revisited: closing the fine-structure-anomaly gap

Affiliations

Moat regimes within a $2 + 1$ flavor Polyakov-quark-meson model

Properties of $X (3872)$ from hadronic potentials coupled to quarks

$^{208}$ Pb nuclear charge radius revisited: closing the fine-structure-anomaly gap