Nuclear Theory·nucl-th

Wednesday·July 12, 2023

11 papers—5 primary·6 cross-listed

01
[Submitted on 11 Jul 2023]
Determination of matter radius and neutron-skin thickness of $^{60, 62, 64}$ Ni from reaction cross section of proton scattering on $^{60, 62, 64}$ Ni targets (published in Results in Physics)
Shingo Tagami · Tomotsugu Wakasa · Masanobu Yahiro
In our previous work, we determined matter radii $r_{m} (exp)$ and neutron-skin thickness $r_{skin} (exp)$ from reaction cross sections $σ_{R} (exp)$ of proton scattering on $^{208}$ Pb, $^{58}$ Ni, $^{40, 48}$ Ca, $^{12}$ C targets, using the chiral (Kyushu) $g$ -matrix folding model with the densities calculated with Gogny-D1S-HFB (D1S-GHFB) with angular momentum projection (AMP). The resultant $r_{skin} (exp)$ agree with the PREX2 and CREX values. As for $^{58}$ Ni, our value is consistent with one determined from the differential cross section for $^{58}$ Ni+ $^{4}$ He scattering. As for p+ $^{60, 62, 64}$ N scattering, $σ_{R} (exp)$ are available as a function of incident energies $E_{in}$ , where $E_{in} = 22.8 \sim 65.5$ ~MeV for $^{60}$ Ni, $E_{in} = 40, 60.8$ ~MeV for $^{62}$ Ni, $E_{in} = 40, 60.8$ ~MeV for $^{64}$ Ni. Our aim is to determine matter radii $r_{m} (exp)$ for $^{60, 62, 64}$ Ni from the $σ_{R} (exp)$ . Our method is the Kyushu $g$ -matrix folding model with the densities scaled from D1S-GHFB+AMP densities, Our skin values are $r_{skin} (exp) = 0.076 \pm 0.019, 0.106 \pm 0.192, 0.162 \pm 0.176$ ~fm, and $r_{m} (exp) = 3.759 \pm 0.011, 3.811 \pm 0.107, 3.864 \pm 0.101$ ~fm for $^{60, 62, 64}$ Ni, respectively.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2307.04974 [pdf]
2 citations
02
[Submitted on 11 Jul 2023]
Effects of neutron-rich nuclei masses on symmetry energy
Seonghyun Kim · Dukjae Jang · Soonchul Choi · Tsuyoshi Miyatsu · Myung-Ki Cheoun
We explore the impact of neutron-rich nuclei masses on the symmetry energy properties using the mass table evaluated by the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) model. First, using the semi-empirical mass formula with the DRHBc mass table, we investigate the symmetry energy at saturation density $ρ_{0}$ , denoted as $S_{0}$ , and the ratio of surface to volume contributions to the symmetry energy, $κ$ . As a result, we obtain $S_{0} = 27.85 MeV$ ( $κ = 1.38$ ) for $a_{sym} (A) = S_{0} (1 - κ A^{- 1/3})$ (Type I) and $S_{0} = 32.66 MeV$ ( $κ = 3.15$ ) for $a_{sym} (A) = S_{0} (1 + κ A^{- 1/3})^{- 1}$ (Type II), which are lower than those obtained using the AME2020 mass table, $S_{0} = 28.54 MeV$ ( $κ = 1.29$ ) for Type I and $S_{0} = 33.81 MeV$ ( $κ = 3.04$ ) for Type II. Second, we further investigate the effect of these changes in $a_{sym} (A)$ on the density-dependent symmetry energy by employing the empirical model of $S (ρ) = C_{k} (ρ / ρ_{0})^{2/3} + C_{1} (ρ / ρ_{0}) + C_{2} (ρ / ρ_{0})^{γ}$ and universal relation of $a_{sym} (A = 208) = S (ρ = 0.1 fm^{- 3})$ . Compared to the experimental constraints, we find that $S_{0}$ and slope parameter $L$ , determined by the DRHBc mass table with Type II, are more suitable to explain the constraints by heavy ion collisions and isobaric analog states than AME2020. We also discuss the neutron skin thickness derived from the $L$ , comparing it with experimental measurements.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2307.05018 [pdf]
0 citations
03
[Submitted on 11 Jul 2023]
Neutron star equation of state: identifying hadronic matter characteristics
Constança Providência🇵🇹 · Tuhin Malik🇵🇹 · Milena Bastos Albino🇵🇹 · Márcio Ferreira🇵🇹
The general behavior of the nuclear equation of state (EOS), relevant for the description of neutron stars (NS), is studied within a relativistic mean field description of nuclear matter. Different formulations, both with density dependent couplings and with non-linear mesonic terms, are considered and their predictions compared and discussed. A special attention is drawn to the effect on the neutron star properties of the inclusion of exotic degrees of freedom as hyperons. Properties such as the speed of sound, the trace anomaly, the proton fraction and the onset of direct Urca processes inside neutron stars are discussed. The knowledge of the general behavior of the hadronic equation of state and the implication it has on the neutron star properties will allow to identify signatures of a deconfinement phase transition discussed in other studies.
Comments:
16 pages, 11 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2307.05086 [pdf]
Chapter "Relativistic Description of the …·25 citations
04
[Submitted on 11 Jul 2023]
Interplay of effects of neutron skins in coordinate space and proton skins in momentum space on hard photons emission in heavy-ion collisions around Fermi Energy
Wen-Mei Guo · Bao-An Li · Gao-Chan Yong
Within an isospin- and momentum-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model, we investigate the hard photons emission from neutron-proton bremsstrahlung in reaction system of $^{208} P b +^{208} P b$ around Fermi energy. Effects of neutron skins in coordinate ( $r$ ) space and proton skins in momentum ( $k$ ) space on the time evolution, the angular distribution, and the transverse momentum spectra of hard photons with different energies are studied. It is shown that the emission of direct hard photons is sensitive to the neutron skin, which has larger effects for more energetic hard photons. Meanwhile, we find that the proton skins have an important influence on the emission of direct hard photons, and its effect is actually even larger than that of neutron skins. It needs to take the effect of proton skins into account when we determine the size of neutron skins by comparing transport mode predictions of hard photons with the corresponding experiment measurements.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2307.05135 [pdf]
PRC(2023)·8 citations
05
[Submitted on 11 Jul 2023]
Quantum entanglement patterns in the structure of atomic nuclei within the nuclear shell model
A. Pérez-Obiol🇪🇸 · S. Masot-Llima🇪🇸 · A.M. Romero🇪🇸 · J. Menéndez🇪🇸 · A. Rios🇪🇸 · A. García-Sáez🇪🇸 · B. Juliá-Díaz🇪🇸
Quantum entanglement offers a unique perspective into the underlying structure of strongly-correlated systems such as atomic nuclei. In this paper, we use quantum information tools to analyze the structure of light and medium-mass berillyum, oxygen, neon and calcium isotopes within the nuclear shell model. We use different entanglement metrics, including single-orbital entanglement, mutual information, and von Neumann entropies for different equipartitions of the shell-model valence space and identify mode-entanglement patterns related to the energy, angular momentum and isospin of the nuclear single-particle orbitals. We observe that the single-orbital entanglement is directly related to the number of valence nucleons and the energy structure of the shell, while the mutual information highlights signatures of proton-proton and neutron-neutron pairing, as well as nuclear deformation. Proton and neutron orbitals are weakly entangled by all measures, and in fact have the lowest von Neumann entropies among all possible equipartitions of the valence space. In contrast, orbitals with opposite angular momentum projection have relatively large entropies, especially in spherical nuclei. This analysis provides a guide for designing more efficient quantum algorithms for the noisy intermediate-scale quantum era.
Comments:
Submitted to EPJA Topical Issue "Quantum computing in low-energy nuclear theory"
Subjects:
Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2307.05197 [pdf]
EPJA(2023)·47 citations
06
[Submitted on 10 Jul 2023] (cross-list from hep-th)
Generalized Hall current on a finite lattice
Srimoyee Sen🇺🇸 · Semeon Valgushev🇺🇸
Gapped fermion theories with gapless boundary fermions can exist in any number of dimensions. When the boundary has even space-time dimensions and hosts chiral fermions, a quantum Hall current flows from the bulk to the boundary in a background electric field. This current compensate for the boundary chiral anomaly. Such a current inflow picture is absent when the boundary theory is odd dimensional. However, in recent work, the idea of quantum Hall current has been generalized to describe odd dimensional boundary theories in continuous Euclidean space-time dimension of infinite volume. In this paper we extend this idea to a lattice regulated finite volume theory of 1+1 dimensional Wilson-Dirac fermions. This fermion theory with a domain wall in fermion mass can host gapless modes on the wall. The number of gapless fermions is equal to the integral of the divergence of the lattice generalized Hall current.
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2307.04792 [pdf]
PRD(2023)·2 citations
07
[Submitted on 10 Jul 2023] (cross-list from hep-ph)
Single-Inclusive Particle Production from $p A$ Collision at Next-to-Leading Order
Heikki Mäntysaari🇫🇮 · Yossathorn Tawabutr🇫🇮
We present the first fully consistent NLO calculation of the single-inclusive forward hadron production in proton-nucleus (pA) collisions under the color glass condensate (CGC) framework. In the dilute-dense limit, the NLO cross-section can be written as a convolution of the NLO impact factor, NLO parton distribution function (PDF), NLO fragmentation function (FF) and dipole-target scattering amplitude which satisfies the NLO small- $x$ Balitsky-Kovchegov (BK) evolution. We demonstrate that, without the NLO corrections to the impact factor, we obtain a significant Cronin peak when the dipole amplitude satisfies the NLO BK equation. This would contradict the recent LHCb results. However, the Cronin peak becomes suppressed when the NLO correction to the impact factor is included. This is the main result of this work. The dependence on resummation schemes for the NLO BK evolution will also be discussed.
Comments:
DIS2023, talk by YT; 9 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.04831 [pdf]
0 citations
08
[Submitted on 10 Jul 2023] (cross-list from hep-ph)
Masses and radiative decay widths of S- and P-wave singly-, doubly- and triply-heavy charm and bottom baryons
Emmanuel Ortiz-Pacheco🇸🇮 · Roelof Bijker🇲🇽
We present a study of mass spectra and electromagnetic couplings of S- and P-wave baryons containing one, two or three heavy quarks, either charm (c) or bottom (b), in the framework of a non-relativistic harmonic oscillator quark model. A simultaneous fit to 41 known masses of heavy baryons (40 singly-heavy and 1 doubly-heavy) shows a r.m.s. deviation of 19 MeV. We present equal-spacing mass rules for excited baryons which may help to assign quantum numbers to experimentally observed heavy baryons. Explicit expressions are derived for electromagnetic couplings, both for spin-flavor matrix elements and radial integrals.
Comments:
26 pages, 7 figures, 27 tables, revised version with note added, accepted for publication in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2307.04939 [pdf]
PRD(2023)·63 citations
09
[Submitted on 11 Jul 2023] (cross-list from nucl-ex)
Decay Pattern of Pygmy States Observed in Neutron-Rich 26 Ne
J. Gibelin🇫🇷 · D. Beaumel🇫🇷 · T. Motobayashi🇯🇵 · Y. Blumenfeld🇫🇷 · N. Aoi🇯🇵 · H. Baba🇯🇵 · Z. Elekes🇭🇺 · S. Fortier🇫🇷 · N. Frascaria🇫🇷 · N. Fukuda🇯🇵 · T. Gomi🇯🇵 · K. Ishikawa🇯🇵 and 14 other authors
Coulomb excitation of the exotic neutron-rich nucleus Ne26 on a Pb208 target was measured at 58 MeV/u in order to search for low-lying E1 strength above the neutron emission threshold. This radioactive beam experiment was carried out at the RIKEN Accelerator Research Facility. Using the invariant mass method in the Ne25+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV excitation energy. By performing a multipole decomposition of the differential cross section, a reduced dipole transition probability of B(E1)=0.49+-0.16e2fm2 is deduced, corresponding to 4.9+-1.6% of the Thomas-Reiche-Kuhn sum rule. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured. The extracted decay pattern is not consistent with several mean-field theory descriptions of the pygmy states.
Comments:
arXiv admin note: text overlap with arXiv:0705.1753
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.05079 [pdf]
PRL(2008)·45 citations
10
[Submitted on 11 Jul 2023] (cross-list from hep-ph)
Heavy-flavor hadronization mechanism from pp to AA collisions: a theoretical perspective
Andrea Beraudo🇮🇹
The interest in studying heavy-flavor hadronization in high-energy nuclear collisions is twofold. On one hand hadronization represents a source of systematic uncertainties in phenomenological attempts of extracting heavy-flavor transport coefficients in the Quark Gluon Plasma which one assumes to be produced in the collision. Hence, developing the most possible reliable model for this process is important to get a precise and accurate estimate of a fundamental property of hot QCD. On the other hand studying how hadronization changes in the presence of a dense medium of colored partons can be considered an issue of interest by itself. In particular, the observation of modifications of heavy-flavor hadronization in proton-proton collisions strongly suggests that also in this case a small droplet of Quark-Gluon Plasma can be formed. Here we try to provide a general overview on heavy-flavor hadronization, from pp to AA collisions, stressing the aspects and challenges common to all mechanisms proposed in the literature. Then, focusing on a particular model, we show how a consistent description of several observables involving heavy-flavor hadrons can be obtained
Comments:
Proceedings of the Hard Probes 2023 conference
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.05286 [pdf]
PoS(2024)·2 citations
11
[Submitted on 11 Jul 2023] (cross-list from nucl-ex)
New Measurements of $^{71}$ Ge Decay: Impact on the Gallium Anomaly
J.I. Collar🇺🇸 · S.G. Yoon🇺🇸
A dedicated high-statistics measurement of the $^{71}$ Ge half-life is found to be in accurate agreement with an accepted value of 11.43 $\pm$ 0.03 d, eliminating a recently proposed route to bypass the "gallium anomaly" affecting several neutrino experiments. Our data also severely constrain the possibility of $^{71}$ Ge decay to low-energy excited levels of the $^{71}$ Ga daughter nucleus as a solution to this puzzle. Additional unpublished measurements of this decay are discussed. Following the incorporation of this new information, the gallium anomaly survives with high statistical significance.
Comments:
3 pages, 2 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.05353 [pdf]
PRC(2023)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE