Nuclear Theory·nucl-th

Friday·November 1, 2024

8 papers—3 primary·5 cross-listed

01
One-proton emission of $^{102}$ Sb and its sensitivity to proton-neutron interaction
Tomohiro Oishi · Masaaki Kimura · Lorenzo Fortunato
One-proton emission from the $^{102}$ Sb nucleus is discussed, assuming an inert $^{100}$ Sn core and the valence proton and neutron. There are experimentally measured bound states in the $^{100}$ Sn-neutron system, whereas no particle-bound $^{100}$ Sn-proton state has been observed. With time-dependent three-body calculations, the $1^{+}$ ground state of $^{102}$ Sb is suggested as a possible proton emitter. This conclusion is reached by assuming a weakening effect on the proton-neutron ( $p n$ ) interaction with respect to a bare deuteron. An analogous phenomenon is necessary to reproduce the empirical binding energies of $^{42}$ Sc and $^{18}$ F. Continuous shift from the unbound to bound regions by changing the $p n$ -interaction strength is demonstrated. The lower limit of lifetime is evaluated as $τ ≳ 4.4 \times 1 0^{- 18}$ seconds in the no- $p n$ -interaction limit. However, the actual lifetime is expected as longer with a finite $p n$ interaction. Observation of a resonant state in $^{102}$ Sb and its decay would provide a benchmark of the $p n$ -pairing correlation.
nucl-thnucl-exPRC(2025)·0 citations
02
Pauli energy contribution to nucleus-nucleus interaction
A.S. Umar🇺🇸 · K. Godbey🇺🇸 · C. Simenel🇦🇺
The investigation delves into understanding how the Pauli exclusion principle influences the bare potential between atomic nuclei through the application of advanced theoretical methodologies. Specifically, the application of the novel Frozen-Hartree-Fock (DCFHF) technique is employed. The resulting potentials demonstrate a noticeable repulsion at short distances, attributed to the effects of the Pauli exclusion principle. To account for dynamic phenomena, such as nucleon transfer processes, the density-constrained time-dependent Hartree-Fock (DC-TDHF) method is utilized. This approach integrates isovector contributions into the potential, shedding light on their influence on fusion reactions. Notably, the inclusion of isovector effects leads to a reduction or enhancement in the inner part of the potential, suggesting a nuanced role of transfer in the fusion process.
nucl-thEPJ Web Conf.(2024)·0 citations
03
A two-body femtoscopy approach to the proton-deuteron correlation function
Juan M. Torres-Rincon🇪🇸 · Angels Ramos🇪🇸 · Joel Rufí🇪🇸
The proton-deuteron correlation function measured by the ALICE collaboration in high multiplicity p+p collisions shows a momentum dependence which is in contradiction with the predictions of the Lednický-Lyuboshitz formalism of the two-body interaction. This result motivated a more sophisticated three-body description in terms of a composite deuteron. Encouraged by the good description of other deuteron observables in the context of heavy-ion collisions, we revisit this correlation function under the two-body approximation without relying on the Lednický-Lyuboshitz approximation, but using the solution of the Schrödinger equation by incorporating both strong and Coulomb interactions. The two-body description provides a reasonable agreement to ALICE data for natural values of the source size. Interpreting the previously assumed attractive character of the $(L, S) = (0, 3/2)$ channel of the $p d$ interaction into a more-likely repulsion, the results agree better not only with the ALICE measurements but also with recent STAR data in Au+Au collisions.
nucl-thhep-phnucl-exPRC(2025)·18 citations
04
Direct nonparametric multimessenger constraints on the equation of state of cold dense nuclear matter
Iuliu Cuceu🇬🇧 · Sandra Robles🇬🇧
We utilize the now substantial amount of astrophysical observations of neutron stars (NSs), along with perturbative quantum chromodynamics (pQCD) calculations at high density, to directly constrain the NS equation of state (EOS). To this end, we construct nonparametric EOS priors by using Gaussian processes trained on 75 EOSs, which include models with either hadrons, hyperons, or quarks at high densities. We create a prior using the full EOS sample (model agnostic), and one prior for each EOS family to test model discrimination. We introduce a novel inference approach, which allows the simultaneous sampling of intrinsic and extrinsic parameters of binary NS mergers, as well as a nonparametric equation of state. We showcase this method in a Bayesian updating scheme by first performing a complete analysis of the binary NS merger event GW170817 with minimal assumptions, and sequentially adding information from x-ray and radio NS observations, along with pQCD calculations. Besides providing standard constraints, such as the pressure at twice nuclear saturation density $p (2 ρ_{sat}) = 4. 3_{- 0.6}^{+ 0.6} \times 1 0^{34} dyne/cm^{2}$ , at $95%$ confidence level, for the model agnostic prior, our methodology shows how the choice of EOS families used in conditioning changes the inferred astrophysical properties of the EOS, namely tidal deformability and maximum supported NS mass. We find hyperonic priors predicting higher tidal deformabilities for a $1.4 M_{⊙}$ NS, and hadronic priors being preferred by the considered astrophysical data.
↳ astro-ph.HEnucl-thPRD(2025)·9 citations
05
Hadronization in small and large systems
Andrea Beraudo🇮🇹
Recent results on particle production in hadronic collisions at the LHC, from proton-proton (pp) to nucleus-nucleus (AA), challenge the traditional paradigm of hadronization as a universal late-time process which can be factorized from the partonic description of the rest of the event. If the violation of this description in nuclear collisions has been accepted for long -- with several hadronic observables finding a natural interpretation assuming some form of recombination of partons from a deconfined medium -- this same occurrence came as a surprise in proton-proton collisions. Actually, strong indications that hadronization cannot be simply described by universal fragmentation fractions/functions were already found in fixed-target experiments, but limited to specific kinematic regions close to the beam rapidity, so that a complete change of paradigm did not look necessary. Here we show that a wide set of observables finds a natural interpretation assuming that in all high-energy hadronic collisions, from pp to AA, a deconfined medium is formed, acting as a reservoir in which a parton can undergo local color neutralization (LCN) through recombination with an opposite color charge. Hadronization, belonging to the non-perturbative domain of QCD, will always, inevitably, require some amount of educated modelling. However, some commong features to the various proposed model in the literature can be identified, which look necessary in order to describe the most recent data. Here we decide to focus on heavy-flavor (HF) production, since in this case the origin of at least one of the consituent quarks of the final hadron is well known and attributed to an initial hard partonic process.
↳ hep-phnucl-thPoS(2025)·2 citations
06
Electric, Magnetic and Quadrupole Form Factors and Charge Radii of Vector Mesons: From Light to Heavy Sector in a Contact Interaction
R. J. Hernández-Pinto🇲🇽 · L. X. Gutiérrez-Guerrero🇲🇽 · M. A. Bedolla🇲🇽 · A. Bashir🇲🇽
We present a detailed survey of electric, magnetic and quadrupole form factors of light and heavy spin-1 vector mesons. It complements our analogous analysis of the electromagnetic form factors of pseudoscalar and scalar mesons reported earlier. Our formalism is based upon the Schwinger-Dyson equations treatment of a vector $\times$ vector contact interaction and the Bethe-Salpeter equation description of relativistic two-body bound states. We compute the form factors, associated moments and charge radii, comparing these quantities to earlier theoretical studies and experimental results if and when possible. We also investigate the quark-mass dependence of the charge radii and find the anticipated hierarchy such that it decreases with increasing dressed quark masses. In addition, our analysis shows that the magnetic moment is independent of the mass of the light and heavy mesons. Our results agree with most measurements reported earlier, finding a negative quadrupole moment, implying the charge distribution is oblate.
↳ hep-phnucl-thPRD(2024)·24 citations
07
Mode analysis of Nambu-Goldstone modes in U(1) charged first-order relativistic viscous hydrodynamics
Atsuhisa Ota🇨🇳
We conduct a mode analysis of a general $U (1)$ -charged first-order relativistic hydrodynamics within the framework of effective field theory for dissipative fluids in flat Minkowski spacetime. We derive the most general quadratic action for hydrodynamic modes, including stochastic noise, and analyze the corresponding dispersion relations in a consistent gradient expansion. We argue that spontaneous breaking of spacetime symmetry arises in the presence of a local thermal state specified by a local timelike four-vector. We demonstrate that hydrodynamical perturbations can be identified as Nambu-Goldstone (NG) modes, analogous to their embedding in global $U (1)$ -invariant theories. We find that frame-invariant combinations of hydrodynamic transport coefficients determine the first-order dispersion relations in the low-energy limit, making the mode analysis manifestly independent of the choice of hydrodynamic frame. Assuming local Kubo-Martin-Schwinger (KMS) symmetry and unitarity of the underlying UV theory, we show that first-order hydrodynamics is stable if the enthalpy density is positive.
↳ hep-thcond-mat.stat-mechgr-qchep-ph+1PRD(2026)·4 citations
08
A generalized picture of colour decoherence in dense QCD media
Samuel Abreu🇨🇭 · Xoán Mayo López🇪🇸 · Guilherme Milhano🇵🇹 · Alba Soto-Ontoso🇪🇸
We revisit the calculation of the soft gluon emission probability off a colour-singlet $q q ˉ$ system that evolves in a quark-gluon plasma. The $q q ˉ$ antenna is created in the presence of a medium and then emits a soft gluon outside. The gluon emission probability is modified with respect to the vacuum baseline due to interactions with the medium during the formation of the antenna and its propagation. Previous studies disregarded the former effect and found that the medium modification to the interference pattern of the antenna was controlled by the so-called critical angle $θ_{c}$ , that exclusively depends on medium properties. We find that accounting for medium interactions during the antenna formation enhances the total rate of emissions off the $q q ˉ$ antenna. Interestingly, it also promotes the notion of a critical angle to a dynamic quantity, denoted $θ ~_{c}$ , that depends on both the medium and the antenna properties and is thus different for every splitting. As a consequence, depending on the region of parameter space, colour decoherence can either be delayed or accelerated with respect to previous estimates.
↳ hep-phhep-exnucl-thJHEP(2025)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE