Nuclear Theory·nucl-th

Thursday·August 15, 2024

11 papers—6 primary·5 cross-listed

01
[Submitted on 13 Aug 2024]
Study of the Log-third-difference method for the computation of even-odd staggering in fission yields
Belén Montenegro Viñas · Manuel Caamaño
The even-odd staggering in fission fragments yield distributions is an important observable to address the role of intrinsic excitations in the fission process. However, its computation as a function of the fragment split is an ill-posed problem that is usually solved through certain assumptions. Arguably, the most widely used method for its computation is the Log-third-difference method, which assumes an underlying local Gaussian distribution. Experimental data of the even-odd effect show sharp features and peaks that are a challenge for the Log-third difference method (or any method for that matter). This paper presents a detailed study of the performance of the Log-third difference method and describes three strategies for improving the precision and accuracy around these sharp features. The best results are obtained with an iterative application of the method and with the use of a multi-Gaussian fit. In regions with a smooth behaviour, the direct application of the Log-third-difference method remains the best option.
Comments:
15 pages, 13 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2408.07173 [pdf]
EPJA(2024)·0 citations
02
[Submitted on 14 Aug 2024]
Pions valence quark distributions in asymmetric nuclear matter at finite temperature
Satyajit Puhan🇮🇳 · Navpreet Kaur🇮🇳 · Arvind Kumar🇮🇳 · Suneel Dutt🇮🇳 · Harleen Dahiya🇮🇳
We have calculated the valence quark distributions of the lightest pseudoscalar meson, pions, in the isospin asymmetric nuclear matter at zero and finite temperature employing a light-cone quark model. The medium modifications in the pion properties have been stimulated through the effective quark masses computed using the chiral SU( $3$ ) quark mean field model. We have primarily focused on the impact of isospin asymmetric medium on the distribution amplitudes (DAs) and parton distribution functions (PDFs) of a valence quark for different baryon density and temperature values. Also, the DAs and PDFs have been evolved to $Q^{2} = 10$ GeV $^{2}$ and $Q^{2} = 16$ GeV $^{2}$ for different densities of nuclear medium and results have been compared with the available experimental data. The DAs and PDFs are found to modify substantially as a function of baryon density as compared to temperature and isospin asymmetry of the medium.
Comments:
26 pages and 10 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2408.07334 [pdf]
PRD(2024)·15 citations
03
[Submitted on 14 Aug 2024]
Survival Probabilities of Compound Superheavy Nuclei Towards Element 119
Yu Qiang · Xiang-Quan Deng · Yue Shi · C.Y. Qiao · Junchen Pei
To synthesize superheavy element 119 is becoming highly concerned as several experimental projects in major laboratories are being pursued. This work studied the survival probabilities of compound superheavy nuclei after multiple neutron emissions based on microscopic energy dependent fission barriers, demonstrating a significant role of triaxial deformation in decreasing the first fission barriers in the heaviest region. Together with the fusion cross sections by the dinuclear system model, the optimal energy and the residual cross section of $^{243}$ Am( $^{48}$ Ca, 3 $n$ ) $^{288}$ Mc are reproduced. Finally the cross sections and optimal beam energies of $^{243}$ Am+ $^{54}$ Cr and $^{249}$ Bk+ $^{50}$ Ti reactions are estimated, providing clues for the synthesis of new elements.
Comments:
5 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2408.07371 [pdf]
PLB(2024)·3 citations
04
[Submitted on 14 Aug 2024]
Quantum Entanglement in Nuclear Fission
Yu Qiang · Junchen Pei · Kyle Godbey
Nuclear fission presents a unique example of quantum entanglement in strongly interacting many-body systems. A heavy nucleus can split into hundreds of combinations of two complementary fragments in the fission process. The entanglement of fragment wave functions is persistent even after separation and impacts the partition of particles and energies between fragments. Based on microscopic dynamical calculations of the fission of $^{240}$ Pu, this work finds that quantum entanglement is indispensable in the appearance of sawtooth distributions of average excitation energies of fragments and thus neutron multiplicities, but not in average neuron excess of fragments. Both sawtooth slopes from particle-number projections are found to be steep -- a feature which can be alleviated by random fluctuations. These findings may impact the understanding of quantum entanglement more broadly in mesoscopic systems.
Comments:
11 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2408.07375 [pdf]
PLB(2025)·17 citations
05
[Submitted on 14 Aug 2024]
Anti-flow of Mesons in the High Baryon Density Region
Zuo-Wen Liu🇨🇳 · Shusu Shi🇨🇳
The E895 and STAR experiments demonstrate that the slopes of directed flow with respect to rapidity ( $d v_{1} / d y ∣_{y = 0}$ ) of mesons are negative in the low transverse momentum ( $p_{T}$ ) region, $p_{T} < 0.8$ GeV/ $c$ , in Au + Au collisions at $s_{N N} = 3.0 - 3.9$ GeV. Using the transport model JAM, we investigate the directed flow of $π^{\pm}$ , $K^{\pm}$ , and $K^{0}$ as functions of rapidity, $p_{T}$ , and collision energy in Au + Au collisions at the same energies as those in the E895 and STAR experiments. We find that the JAM model can qualitatively reproduce the anti-flow of $K_{S}^{0}$ observed in the E895 experiment. The $v_{1}$ slopes of pions and kaons are analyzed as functions of the $p_{T}$ window, revealing a strong $p_{T}$ dependence of the $v_{1}$ slopes. Negative $v_{1}$ slopes are observed in the low $p_{T}$ region, $p_{T} < 0.8$ GeV/ $c$ , while positive slopes are shown in the higher $p_{T}$ region. We find that the shadowing effect from spectators is crucial in generating the anti-flow of mesons at low $p_{T}$ in the high baryon density region.
Comments:
7 pages, 7 figures, accepted by Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2408.07563 [pdf]
PRC(2024)·6 citations
06
[Submitted on 14 Aug 2024]
A study of bound states of $η, η^{^{'}}, D^{0}$ , $D^{0} ˉ$ , $B^{0}$ , $B^{0} ˉ$ , $K^{0} ˉ$ and $ϕ$ mesons with light and heavy nuclei within chiral SU(3) model
Arvind Kumar🇮🇳 · Amruta Mishra🇮🇳
In the present work we explore the possibilities of the formation of bound states of neutral pseudoscalar mesons $η, η^{^{'}}, D^{0}$ , $D^{0} ˉ, B^{0}, B^{0} ˉ$ and $K^{0} ˉ$ and the vector meson $ϕ$ , with the nuclei $^{12}$ C, $^{16}$ O, $^{40}$ Ca and $^{208}$ Pb, calculating their binding energy and absorption decay width. To calculate the optical potentials of these mesons in different nuclei under study, we shall use the chiral SU(3) hadronic mean field model, in which the properties of nucleons in the medium are modified through the scalar isoscalar fields $σ$ and $ζ$ and the scalar-isovector field $δ$ . The scalar-isovector field $δ$ account for the finite isospin asymmetry of different nuclei having asymmetry in number of protons and neutrons. The binding energy and absorption decay width of mesons are calculated for the ground state and some of possible excited states of the nuclei. In the chiral SU(3) model, the mesons $η, D^{0}$ , $D^{0} ˉ, B^{0}, B^{0} ˉ$ and $K^{0} ˉ$ are observed to have significant negative mass shift upto nuclear saturation density which lead to the possibility of the bound states at least for ground states and some of excited states in case of heavy nuclei. For the pseudoscalar singlet $η^{^{'}}$ and the vector meson $ϕ$ the mass shift obtained are found to be small and bound states are not formed. The present calculations are compared with different studies available in the field and will be useful in understanding the outcomes from different experimental facilities focusing on this area of research.
Comments:
40 pages, 11 figures, Accepted for publication in Chinese Physics C
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2408.07633 [pdf]
CPC(2025)·3 citations
07
[Submitted on 12 Aug 2024] (cross-list from hep-ph)
Testing for coherence and nonstandard neutrino interactions in COHERENT data
Jiajun Liao🇨🇳 · Danny Marfatia🇺🇸 · Jiajie Zhang🇨🇳
We analyze data from the CsI, liquid Ar and Ge detectors of the COHERENT experiment and confirm within $1.5 σ$ that the measured elastic neutrino-nucleus scattering cross section is proportional to the square of the number of neutrons in the nucleus, as expected for coherent scattering in the standard model. We also show how various degeneracies involving nonstandard neutrino interaction parameters are broken in a combined analysis of the three datasets.
Comments:
10 pages, 8 figures, 1 table. Version to appear in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2408.06255 [pdf]
PRD(2024)·11 citations
08
[Submitted on 13 Aug 2024] (cross-list from hep-ph)
Are in-medium quark-gluon showers strongly coupled? Results in the large- $N_{f}$ limit
Peter Arnold🇺🇸 · Omar Elgedawy🇺🇸 · Shahin Iqbal🇵🇰
Inside a medium, showers originating from a very high energy particle develop via medium-induced splitting processes such as bremsstrahlung and pair production. During shower development, two consecutive splittings sometimes overlap quantum mechanically, so that they cannot be treated independently. Some of these effects can be absorbed into an effective value of a medium parameter known as $q^$ . Previous calculations (with certain simplifying assumptions) have found that, after adjusting the value of $q^$ , the leftover effect of overlapping splittings is quite small for purely gluonic large- $N_{c}$ showers but is very much larger for large- $N_{f}$ QED showers, at comparable values of $N α$ . Here, by investigating the same problem for QCD with *quarks* in the large- $N_{f}$ limit of many quark flavors, we make a first study of whether the small effect in purely gluonic showers (i) was merely an accident or (ii) is more broadly characteristic of such overlap effects in QCD. We also offer a qualitative explanation for the large size of the effect in QED vs. QCD.
Comments:
74 pages, 25 figures; changes from v1: slight clarification added on a few points and a few typos fixed
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2408.07129 [pdf]
JHEP(2025)·13 citations
09
[Submitted on 13 Aug 2024] (cross-list from hep-ph)
Search for baryon junctions in e+A collisions at the Electron Ion Collider
Niseem Magdy🇺🇸 · Abhay Deshpande🇺🇸 · Roy Lacey🇺🇸 · Wenliang Li🇺🇸 · Prithwish Tribedy🇺🇸 · Zhangbu Xu🇺🇸
Constituent quarks in a nucleon are the essential elements in the standard ``quark model" associated with the electric charge, spin, mass, and baryon number of a nucleon. Quantum Chromodynamics (QCD) describes nucleon as a composite object containing current quarks (valence quarks and sea (anti-)quarks) and gluons. These subatomic elements and their interactions are known to contribute in complex ways to the overall nucleon spin and mass. In the early development of QCD theory in the 1970s, an alternative hypothesis postulated that the baryon number might manifest itself through a non-perturbative configuration of gluon fields forming a Y-shaped topology known as the gluon junction. In this work, we propose to test such hypothesis by measuring (i) the Regge intercept of the net-baryon distributions for $e$ +( $p$ )Au collisions, (ii) baryon and charge transport in the isobaric ratio between $e$ +Ru and $e$ +Zr collisions, and (iii) target flavor dependence of proton and antiproton yields at large rapidity, transported from the hydrogen and deuterium targets in $e + p$ (d) collisions. Our study indicates that these measurements at the EIC can help determine what carries the baryon number.
Comments:
7 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2408.07131 [pdf]
EPJC(2024)·3 citations
10
[Submitted on 13 Aug 2024] (cross-list from hep-ph)
TMD phenomenology motivated by nonperturbative structures
Ted Rogers🇺🇸 · Fatma Aslan🇺🇸 · Mariaelena Boglione🇮🇹 · J. Osvaldo Gonzalez-Hernandez🇮🇹 · Tommaso Rainaldi🇺🇸 · Andrea Simonelli🇺🇸
This talk summarized work done recently to organize the steps for implementing TMD phenomenology in a way optimized for contexts where the extraction and interpretation of hadronic structures and nonperturbative effects is the primary driving motivation.
Comments:
17 pages, proceedings of 7th International Workshop on Transverse phenomena in hard processes and the transverse structure of the proton (Transversity2024)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2408.07170 [pdf]
PoS(2024)·3 citations
11
[Submitted on 14 Aug 2024] (cross-list from hep-ph)
Dihadron azimuthal asymmetry and light-quark dipole moments at the Electron-Ion Collider
Xin-Kai Wen🇨🇳 · Bin Yan🇨🇳 · Zhite Yu🇺🇸 · C.-P. Yuan🇺🇸
We propose a novel method to probe light-quark dipole moments by examining the azimuthal asymmetries between a collinear pair of hadrons in semi-inclusive deep inelastic lepton scattering off an unpolarized proton target at the Electron-Ion Collider. These asymmetries provide a means to observe transversely polarized quarks, which arise exclusively from the interference between the dipole and the Standard Model interactions, thereby depending linearly on the dipole couplings. We demonstrate that this novel approach can enhance current constraints on light-quark dipole operators by an order of magnitude, free from contamination of other new physics effects. Furthermore, it allows for a simultaneous determination of both the real and imaginary parts of the dipole couplings, offering a new avenue for investigating potential $C P$ -violating effects at high energies.
Comments:
7 pages, 2 figures, published version in SCPMA
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2408.07255 [pdf]
SCPMA(2026)·31 citations

Affiliations

first authorsco-authorsvia INSPIRE