Nuclear Theory·nucl-th

Thursday·November 28, 2024

15 papers—5 primary·10 cross-listed

06
Chiral effective theory of scalar and vector diquarks revisited
Yonghee Kim🇯🇵 · Makoto Oka🇯🇵 · Kei Suzuki🇯🇵
Chiral effective theory of light diquarks is revisited. We construct an effective Lagrangian based on the linear representation of three-flavor chiral symmetry. Here, we focus on the effect of a chiral and $U (1)_{A}$ symmetric term originated from an eight-point quark interaction. From this model, we obtain the mass formulas of scalar, pseudoscalar, vector, and axial-vector diquarks, which also describe the dependence of diquark masses on the spontaneous chiral symmetry breaking and the $U (1)_{A}$ anomaly. We regard singly heavy baryons as two-body systems composed of one heavy quark and one diquark and then predict the fate of the mass spectrum and the strong decay widths under chiral symmetry restoration.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·7 citations
07
CP violation in cold dense quark matter and axion effects on the non-radial oscillations of neutron stars
Deepak Kumar🇮🇳 · Hiranmaya Mishra🇮🇳
Charge-conjugation and parity violation in strong interaction for cold dense quark matter is studied with axions of quantum chromodynamic within the three flavor Nambu--Jona-Lasinio model that includes the coupling of axions to quarks. We first calculate the effective potential for axions at finite baryon density and zero temperature including the effects of a first order chiral phase transition. Using the equation of state for quark matter with axions and a hadronic matter equation of state in the ambit of a relativistic mean field theory in quantum hadrodynamics, we discuss the hadron-quark phase transition. Inclusion of axions reduces the critical density for chiral transition. We use a Gibbs construct for the hadron-quark phase transition satisfying the constraints of beta equilibrium and charge neutrality as appropriate for the neutron star matter. The equation of state so obtained is used to investigate the structure of hybrid neutron stars. It is found that with the presence of axions, it is possible to have stable hybrid neutron stars having an inner core of quark matter both in pure quark matter phase as well as in a mixed phase with hyperonic matter along with a outer core of hyperonic matter and is in agreement with modern astrophysical constraints. We also discuss the properties of non-radial oscillations of such hybrid neutron stars. It is observed that the quadrupolar fundamental modes ( $f$ -modes) for such hybrid neutron stars get substantial enhancements both due to a larger quark core in the presence of axions and from the hyperons as compared to a canonical nucleonic neutron stars.
↳ hep-phastro-ph.HEnucl-thJCAP(2026)·11 citations
08
"Nuclear thermometers" reveal the origin of the universal r-process nucleosynthesis
José Nicolás Orce
The resembling behaviour of giant dipole resonances built on ground and excited states supports the validity of the Brink-Axel hypothesis and assigns giant dipole resonances as spectroscopic probes -- or ``nuclear thermometers'' -- to explore the cooling of the kilonova ejecta in neutron-star mergers down to the production of heavy elements beyond iron through the rapid-neutron capture or r-process. In previous work, we found a slight energy increase in the giant dipole resonance built on excited states at the typical temperatures of $1.0 ⪆ T ⪆ 0.7$ MeV where seed nuclei are produced, before ongoing neutron capture. Crucial data are presented here supporting an enhanced symmetry energy at $T = 0.51$ MeV (or $5.9 \times 1 0^{9}$ K) -- where the r-process occurs -- that lowers the binding energy in the Bethe-Weizsäcker semi-empirical mass formula and results in the close in of the neutron drip line. Ergo, providing an origin to the universality of elemental abundances by limiting the reaction network for r-process nucleosynthesis. An enhanced symmetry energy away from the ground state is further supported by shell-model calculations of the nuclear electric dipole ({\sc E1}) polarizability -- inversely proportional to the symmetry energy -- as a result of the destructive contribution of the products of off-diagonal {\sc E1} matrix elements.
↳ astro-ph.SRnucl-exnucl-th0 citations
09
Fully charmed P-wave tetraquark resonant states in the quark model
Wei-Lin Wu🇨🇳 · Shi-Lin Zhu🇨🇳
We conduct the first comprehensive P-wave four-body dynamical calculations of the fully charmed tetraquark systems within the quark potential model. We apply the Gaussian expansion method to solve the four-body Schrödinger equation, incorporating both dimeson and diquark-antidiquark spatial configurations. The matrix elements of P-wave states are calculated analytically using the infinitesimally-shifted Gaussian basis functions. With the complex scaling method, we obtain several fully charmed P-wave resonant states with compact tetraquark configuration in the mass region of $(7.0, 7.2)$ GeV, including states with exotic quantum numbers $J^{P C} = 0^{--}, 1^{-+}$ . However, we find no resonant states with the mass $M < 7$ GeV and width $Γ < 200$ MeV. Combining the present investigation with our previous results on S-wave fully charmed tetraquark systems, we find no candidates for the experimental states $X (6400)$ and $X (6600)$ in the quark model.
↳ hep-phhep-exhep-latnucl-thPRD(2025)·11 citations
10
The Equation of State and Multiparticle Production
R. N. Rogalyov🇷🇺
We discuss the distribution of fireballs produced in heavy-ion collisions in the net-baryon number and argue that neither the Free-Quark Model (FQM) nor the Hadron Resonance Gas (HRG) model can provide a comprehensive explanation of the distribution observed at the LHC. The concept of net-baryon number freezeout temperature is suggested and the role of sea quarks as a possible source of net-baryon number fluctuations is emphasized.
↳ hep-phnucl-thPhys.Part.Nucl.(2024)·0 citations
11
On the possible existence of a $S = - 3, I = 1$ pentaquark
Albert Feijoo🇩🇪 · Isaac Vidaña🇮🇹
We analyze the possible existence of a strangeness $S = - 3$ , isospin $I = 1$ pentaquark state $P_{sss}$ generated dynamically from the $K ˉ Ξ$ interaction. We employ a unitarized scheme in coupled channels based on the chiral Lagrangian expanded up to next-to-leading order (NLO), and show that the inclusion of the NLO terms is crucial to provide the necessary attraction that favors the existence of such triply strange pentaquark. The $K ˉ Ξ$ femtoscopic correlation functions are calculated as example of a possible experimental measurement in which a direct signal of the $P_{sss}$ state could be observed.
↳ hep-phhep-thnucl-thEPJA(2025)·6 citations
12
Production of exotic hadrons in $pp$ and nuclear collisions
Jinhui Chen · Feng-Kun Guo · Yu-Gang Ma · Cheng-Ping Shen · Qiye Shou · Qian Wang · Jia-Jun Wu · Bing-Song Zou
Exotic hadrons beyond the conventional quark model have been discovered in the past two decades. Investigations of these states can lead to deep understanding of nonperturbative dynamics of the strong interaction. In this concise review, we focus on the productions of exotic hadrons in $pp$ , $p p ˉ$ , and nuclear collisions. Experimental observations of light nuclei and hypernuclei, as prototypes of hadronic molecules, in heavy ion collisions will also be briefly discussed.
↳ hep-phhep-exnucl-exnucl-thNucl.Sci.Tech.(2025)·47 citations
13
On formation of the $^{12}$ C(0 $_{2}^{+}$ ) and $^{12}$ C(3 $^{-}$ ) states in relativistic dissociation of light nuclei
A.A. Zaitsev · P.I. Zarubin
The formation of the excited states $^{12}$ C(0 $_{2}^{+}$ ) and $^{12}$ C(3 $^{-}$ ) is investigated in the dissociation of $^{12}$ C $\to$ 3 $α$ and $^{16}$ O $\to$ 4 $α$ at the energy of 3.65 GeV per nucleon in the nuclear emulsion. The identification becomes possible by reconstructing the invariant mass from measurements of emission angles in the approximation of conservation of momentum per nucleon of the parent nucleus. The contribution of the decays $^{12}$ C(0 $_{2}^{+}$ ) and $^{12}$ C(3 $^{-}$ ) to the dissociation $^{12}$ C $\to$ 3 $α$ is 11 and 19%, and in $^{16}$ O $\to$ 4 $α$ it is - 20 and 30%, correspondingly.
↳ nucl-exnucl-thPhys.Atom.Nucl.(2025)·0 citations
14
Collectivity in ultra-peripheral heavy-ion and e+A collisions
Björn Schenke · Chun Shen · Wenbin Zhao
We review recent theoretical progress in describing collective effects in photon+nucleus collisions. The approaches considered range from the color glass condensate where correlations are encoded in the initial state, to hydrodynamic frameworks, where a strong final state response to the initial geometry of the collision is the key ingredient to generate momentum-space correlations.
↳ hep-phnucl-thActa Phys.Polon.Supp.(2025)·3 citations
15
Re examination of \b{eta} decay in Hg, Pb and Po Isotopes
Jameel-Un Nabi · Tuncay Bayram · Muhammad Riaz · Asim Ullah · Anes Hayder · Sevki Senturk · Mahmut Boyukata
This study re examines the effect of nuclear deformation on the calculated Gamow Teller (GT) strength distributions of neutron deficient (178 192Hg, 185 194Pb and 196 206Po) nuclei. The nuclear ground state properties and shape parameters were calculated using the Relativistic Mean Field model. Three different density dependent interactions were used in the calculation. Estimated shape parameters were later used within the framework of deformed proton-neutron quasi random phase approximations model, with a separable interaction, to calculate the GT strength distributions, half lives and branching ratios for these neutron deficient isotopes. It was concluded that half lives and GT strength distributions vary considerably with change in shape parameter.
↳ astro-ph.SRnucl-thPhys.Scripta(2023)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE