Nuclear Theory·nucl-th

Wednesday·March 19, 2025

13 papers—6 primary·7 cross-listed

01
[Submitted on 18 Mar 2025]
Investigation of effects of pairing correlations on calculated $β$ -decay half-lives of fp-shell nuclei
Asim Ullah · Jameel-Un Nabi · Muhammad Tahir
Pairing of nucleons plays a key role in solving various nuclear physics problems. We investigate the probable effects of pairing correlations on the calculated Gamow-Teller (GT) strength distributions and the associated $β$ -decay half-lives. Computations are performed for a total of 35 fp-shell nuclei using the proton-neutron quasiparticle random phase approximation (pn-QRPA) model. The nuclei were selected because of their importance in various astrophysical environments. Pairing gaps are one of the key parameters in the pn-QRPA model to compute GT transitions. We employed three different values of the pairing gaps obtained from three different empirical formulae in our calculation. The GT strength distributions changed significantly as the pairing gap values changed. This in turn resulted in contrasting centroid and total strength values of the calculated GT distributions and led to differences in calculated half-lives using the three schemes. The half-life values computed via the three-term pairing formula, based on separation energies of nucleons, were in best agreement with the measured data. We conclude that the traditional choice of pairing gap values, $Δ_{p} = Δ_{n} = 12/ A$ , may not lead to half-life values in good agreement with measured data. The findings of this study are interesting but warrant further investigation.
Comments:
11 Pages, 8 Tables, 2 Figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2503.13889 [pdf]
Braz.J.Phys.(2023)·3 citations
02
[Submitted on 18 Mar 2025]
Influence of the effective mass on the properties of nuclear matter at finite density and temperature
Hajime Togashi🇰🇷 · Debashree Sen🇰🇷 · Hana Gil🇰🇷 · Chang Ho Hyun🇰🇷
Significance of the chiral symmetry restoration is studied by considering the role of the modification of the nucleon mass in nuclear medium at finite density and temperature. Using the Korea-IBS-Daegu-SKKU density functional theory, we can create models that have an identical nuclear matter equation of state but different isoscalar and isovector effective masses at zero temperature. Effect of the effective mass becomes transparent at non-zero temperatures, and it becomes more important as temperature increases. Role of the effective mass is examined thoroughly by calculating the dependence of thermodynamic variables such as free energy, internal energy, entropy, pressure and chemical potential on density, temperature and proton fraction. We find that sensitivity to the isoscalar effective mass is several times larger than that of the isovector effective mass, so the uncertainties arising from the effective mass are dominated by the isoscalar effective mass. In the analysis of the relative uncertainty, we obtain that the maximum uncertainty is less than 2% for free energy, internal energy and chemical potential, but it amounts to 20% for pressure. Entropy shows a behavior completely different from the other four variables that the uncertainty is about 40% at the saturation density and increases monotonically as density increases. Effect of the uncertainty to properties of physical systems is investigated with the proto-neutron star. It is shown that temperature depends strongly on the effective mass at a given density and substantial swelling of the radius occurs due to the finite temperature. Equation of state is stiffer with smaller isoscalar effective mass, so the effect of the effective mass appears clearly in the mass-radius relation of the proto-neutron star, larger radius corresponding to smaller effective mass.
Comments:
16 pages; 15 figures; Journal : Symmetry (Special Issue Chiral Symmetry, and Restoration in Nuclear Dense Matter)
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2503.13963 [pdf]
Symmetry(2025)·6 citations
03
[Submitted on 18 Mar 2025]
Electron capture and \b{eta}-decay rates for nuclei with A=65-80
Asim Ullah · Jameel-Un Nabi
Recently, a list of the top 50 most important electron capture (EC) and $β$ -decay (BD) nuclei, averaged throughout the stellar trajectory for $0.500 > Y_{e} > 0.400$ , was published. The current study presents the calculation of EC and BD rates, from the published list with $A = 65 - 80$ , on a detailed temperature-density grid. The EC and BD rates were calculated using the proton-neutron quasiparticle random phase approximation model (pn-QRPA). Our calculation did not employ the Brink-Axel hypothesis. A systematic comparison of the current calculation with previous pn-QRPA and independent particle model (IPM) results is presented for the first time. The reported EC rates are nearly the same when compared with the previous pn-QRPA calculation. On the other hand, the reported BD rates are generally smaller by up to an order of magnitude. Comparison with IPM results shows that our calculated rates are larger by two orders of magnitude. The current calculation may contribute to a more realistic simulation of the late phases of stellar evolution and the modeling of X-ray bursts.
Comments:
14 Pages, 9 Tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2503.14010 [pdf]
Phys.Scripta(2022)·0 citations
04
[Submitted on 18 Mar 2025]
Delayed Thermal Relaxation of Rapidly Cooling Neutron Stars: Nucleon Superfluidity and Non-nucleon Particles
Zhonghao Tu · Ang Li
The thermal relaxation time of neutron stars, typically defined by a sudden drop in surface temperature, is usually on the order of 10 to 100 years. In this study, we investigate neutron star thermal relaxation by incorporating nucleon superfluidity and non-nucleonic particles, specifically considering hyperons as a representative case. We find that rapidly cooling neutron stars driven by neutron superfluidity and direct Urca processes demonstrate delayed thermal relaxation under specific physical conditions. The former acquires that the neutron $^{3} P_{2}$ critical temperature is small enough, whereas the latter depends on the presence of a small core that permits direct Urca processes. To explore these scenarios, we propose simple theoretical frameworks to describe these delayed thermal relaxation behaviors and discuss how an recently-established enhanced modified Urca rate influences the relaxation time. By confronting the theoretical results with the observation of Cassiopeia A, we can effectively constrain the maximum neutron $^{3} P_{2}$ critical temperature.
Comments:
version accepted for publication in ApJ
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
arXiv:
2503.14059 [pdf]
ApJ·3 citations
05
[Submitted on 18 Mar 2025]
Investigation of $β$ -decay properties of neutron-rich Cerium isotopes
Jameel-Un Nabi · Asim Ullah · Zeeshan Khan
Reliable and precise knowledge of the $β$ -decay properties of neutron-rich nuclei is important for a better understanding of the $r$ -process. We report the computation of $β$ -decay properties of neutron-rich Cerium isotopes calculated within the proton-neutron quasiparticle random phase approximation (pn-QRPA) approach. A total of 34 isotopes of Ce in the mass range $120 \leq A \leq 157$ were considered in our calculation. Pairing gaps are recognized amongst the key parameters in the pn-QRPA model to compute Gamow-Teller (GT) transitions. We employed two different values of the pairing gaps obtained from two different empirical formulae in our computation. The GT strength distributions changed considerably with changes in the pairing gap values. This, in turn, resulted in contrasting centroid and total strength values of the GT distributions and led to differences in calculated half-lives using the two schemes. The traditional pairing gaps resulted in significant fragmentation of GT strength. However, the pairing gaps, calculated employing the formula based on separation energies of neutron and proton, led to computed half-lives in better agreement with the measured data.
Comments:
17 Pages, 5 Tables, 1 Figure
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2503.14323 [pdf]
Phys.Scripta(2022)·1 citation
06
[Submitted on 18 Mar 2025]
Nuclear configurational complexity in high-energy hadron-hadron scatterings
G. Karapetyan🇧🇷
This paper investigates high-energy hadron-hadron scattering utilizing AdS/QCD correspondence, gravitational form factors, and the Brower-Polchinski-Strassler-Tan pomeron exchange kernel. We use the configurational complexity to estimate the slope of the total cross section for hadron-hadron interactions at the high-energy regime. Our approach agrees well with the phenomenological cross sections regulated by Pomeron exchange involving the pion-nucleon, nucleon-nucleon, and pion-pion, in data from the TOTEM collaboration (LHC). In the case of pion-nucleon and pion-pion scattering, the agreement for the global critical point of the configurational complexity has good accuracy within 2.3\%.
Comments:
8 pages, 1 figure
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2503.14410 [pdf]
0 citations
07
[Submitted on 15 Mar 2025] (cross-list from hep-ph)
Isospin sum rules for bottom-baryon weak decays
Wei-Chen Fu🇨🇳 · Si-Jia Wen🇨🇳 · Di Wang🇨🇳
Isospin symmetry, as the most precise flavor symmetry, can be used to extract information about hadronic dynamics. The effective Hamiltonian operators of bottom quark weak decays are zero under a series of isospin lowering operators $I_{-}^{n}$ , which permits us to generate isospin sum rules without the Wigner-Eckart invariants. In this work, we derive hundreds of isospin sum rules for the two- and three-body non-leptonic decays of bottom baryons. They provide hints for new decay modes and the isospin partners of pentaquark states.
Comments:
50 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2503.13527 [pdf]
EPJC(2025)·3 citations
08
[Submitted on 17 Mar 2025] (cross-list from hep-ph)
Dissecting Jet Modification in the QGP with Multi-Point Energy Correlators
João Barata🇨🇭 · Ian Moult🇺🇸 · Andrey V. Sadofyev🇵🇹 · João M. Silva🇵🇹
Energy correlators have recently attracted significant attention in the study of heavy ion collisions due to their potential to robustly connect experimental measurements with an underlying quantum field theoretic description. While theoretical studies have so far primarily focused on the simplest two-point correlator, mapping out the dynamics of the quark-gluon plasma (QGP) will require developing a theoretical understanding of multi-point energy correlators. In this paper we present a systematic theoretical study of multi-point energy correlators for jets fragmenting in a dense quark-gluon plasma, accounting for both the medium's perturbative modification to the jet, and its hydrodynamical back-reaction. We consider both the scaling behavior of projected correlators, as well as the shape dependent three-point correlator, highlighting how both provide insight into interactions with the QGP. We discuss the parametric dependence of modifications on the medium scales, opening new opportunities to experimentally separate jet modifications from the medium response. Our results open the door to a systematic exploration of multi-point energy correlators in heavy ion collisions.
Comments:
10 pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2503.13603 [pdf]
PRL(2026)·32 citations
09
[Submitted on 17 Mar 2025] (cross-list from astro-ph.HE)
Comprehensive Analysis of Constructing Hybrid Stars with an RG-consistent NJL Model
Jan-Erik Christian🇩🇪 · Ishfaq Ahmad Rather🇩🇪 · Hosein Gholami🇩🇪 · Marco Hofmann🇩🇪
In this work, we investigate the properties of hadronic and quark matter that would allow for a first order phase transition between them within neutron stars. To this end, we use a parameterizable Relativistic Mean-Field (RMF) description for the hadronic phase and a Renormalization Group-consistent Nambu-Jona-Lasino (RG-NJL) model for the quark phase. This also enables us to consider sequential phase transitions involving a two-flavor color-superconducting (2SC) and a color-flavor-locked (CFL) phase. We find large ranges for all parameters that facilitate a phase transition, even when constrained by current astrophysical data. We further attempt to filter out stars with a high chance of detectability by mass-radius measurement, i.e., stars with identical mass but different radii, so-called twin stars. However, we find that such configurations are outside the constrained parameter spaces. Instead, most of the mass-radius relations that feature a phase transition appear to be indistinguishable from a purely hadronic description.
Comments:
13 pages, 5 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2503.13626 [pdf]
Astron.Astrophys.(2025)·30 citations
10
[Submitted on 18 Mar 2025] (cross-list from hep-ph)
Investigations of symmetry breakings by multiple condensates on exotic chiral condensed phases
Joshua Murakami (Kochi Univ., Japan)🇯🇵 · Kentaro Hayashi (Kochi Univ., Japan)🇯🇵 · Yasuhiko Tsue (Kochi Univ., Japan)🇯🇵
The Nambu-Goldstone modes on the exiotic chiral condensed phase with chiral and tensor-type quark-antiquark condensates are investigated by using of the two-point vertex functions. It is shown that one of the Nambu-Goldstone modes appears as a result of meson-mixing. As is well known, another method to find the Nambu-Goldstone modes is given by the use of the algebraic commutation relations between broken generators and massless modes obtained through the spontaneous symmetry breaking. This method is adopted to the cases of the chiral symmetry breakings due to the tensor-type condensate and the inhomogeneous chiral condensate. The result obtained by the use of the meson two-point vertex functions is obviously reproduced in the case of the tensor-type condensate. Furthermore, we investigate the general rules for determining the broken symmetries and the Nambu-Goldstone modes algebraically. As examples, the symmetry breaking pattern and the Nambu-Goldstone modes due to the tensor-type condensate or the inhomogeneous chiral condensate are shown by adopting the general rules developed in this paper in the algebraic method.
Comments:
16 pages, No figure
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2503.13845 [pdf]
PRD(2025)·0 citations
11
[Submitted on 18 Mar 2025] (cross-list from hep-lat)
Lattice Monte Carlo meets lattice functional Renormalization Group: A quantitative comparison
Niklas Zorbach🇩🇪 · Jan Philipp Klinger🇩🇪 · Owe Philipsen🇩🇪 · Jens Braun🇩🇪
Lattice Monte Carlo (MC) simulations and the functional Renormalization Group (RG) are powerful approaches that allow for quantitative studies of non-perturbative phenomena such as bound-state formation, spontaneous symmetry breaking and phase transitions. While results from both methods have recently shown remarkable agreement for many observables, e.g., in Quantum Chromodynamics, an analysis of deviations in certain quantities turns out to be challenging. This is because calculations with the two methods are based on different approximations, regularizations and scale fixing procedures. In the present work, we present a framework for a more direct comparison by formulating the functional RG approach on a finite spacetime lattice. This removes all ambiguities of regularization, finite size and scale fixing procedures in concrete studies. By investigating the emergence of spontaneous symmetry breaking and phase transitions in a $Z (2)$ scalar theory in $d = 1, 2, 3$ spacetime dimensions, we demonstrate at the example of the local potential approximation how this framework can be used to evaluate and compare the systematic errors of both approaches.
Comments:
22 pages, 10 figures, 1 table
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2503.14149 [pdf]
PRD(2025)·3 citations
12
[Submitted on 18 Mar 2025] (cross-list from hep-ph)
Double parton interactions initiated by direct photons in $γ p$ and $γ A$ collisions revisited
B. Blok (Technion)🇮🇱 · R. Segev (Technion)🇮🇱
We consider the double parton scattering (DPS) initiated by direct photons in $γ p$ and $γ A$ collisions. We extend the previously known results for photoproduction to the case of electroproduction with nonzero photon virtuality $Q^{2}$ , and then consider the DPS for both photo and electroproduction for HERA and IEC ( electron ion collider) kinematics. The number of DPS events at IEC is shown to be of the same order as in HERA and is even larger, with increase in luminocity compensating the decrease of the center of mass energy.
Comments:
25 pages,12 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2503.14152 [pdf]
PRD(2026)·4 citations
13
[Submitted on 18 Mar 2025] (cross-list from astro-ph.IM)
Strategic White Paper on AI Infrastructure for Particle, Nuclear, and Astroparticle Physics: Insights from JENA and EuCAIF
Sascha Caron🇳🇱 · Andreas Ipp🇦🇹 · Gert Aarts🇬🇧 · Gábor Bíró🇭🇺 · Daniele Bonacorsi🇮🇹 · Elena Cuoco🇮🇹 · Caterina Doglioni🇬🇧 · Tommaso Dorigo🇸🇪 · Julián García Pardiñas🇺🇸 · Stefano Giagu🇮🇹 · Tobias Golling🇨🇭 · Lukas Heinrich🇩🇪 and 7 other authors
Artificial intelligence (AI) is transforming scientific research, with deep learning methods playing a central role in data analysis, simulations, and signal detection across particle, nuclear, and astroparticle physics. Within the JENA communities-ECFA, NuPECC, and APPEC-and as part of the EuCAIF initiative, AI integration is advancing steadily. However, broader adoption remains constrained by challenges such as limited computational resources, a lack of expertise, and difficulties in transitioning from research and development (R&D) to production. This white paper provides a strategic roadmap, informed by a community survey, to address these barriers. It outlines critical infrastructure requirements, prioritizes training initiatives, and proposes funding strategies to scale AI capabilities across fundamental physics over the next five years.
Comments:
19 pages, 5 figures
Subjects:
Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); cs.AI (cs.AI); Machine Learning (cs.LG); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2503.14192 [pdf]
Mach.Learn.Sci.Tech.(2026)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE