Nuclear Theory·nucl-th

Monday·October 24, 2022

19 papers—10 primary·9 cross-listed

01
[Submitted on 21 Oct 2022]
Neutron star mass formula with nuclear saturation parameters for asymmetric nuclear matter
Hajime Sotani · Shinsuke Ota
Low-mass neutron stars are directly associated with the nuclear saturation parameters because their central density is definitely low. We have already found a suitable combination of nuclear saturation parameters for expressing the neutron star mass and gravitational redshift, i.e., $η \equiv (K_{0} L^{2})^{1/3}$ with the incompressibility for symmetric nuclear matter, $K_{0}$ , and the density-dependent nuclear symmetry energy, $L$ . In this study, we newly find another suitable combination given by $η_{τ} \equiv (- K_{τ} L^{5})^{1/6}$ with the isospin dependence of incompressibility for asymmetric nuclear matter, $K_{τ}$ , and derive the empirical relations for the neutron star mass and gravitational redshift as a function of $η_{τ}$ and the normalized central number density. With these empirical relations, one can evaluate the mass and gravitational redshift of the neutron star, whose central number density is less than threefold the saturation density, within $\sim 10%$ accuracy, and the radius within a few \% accuracies. In addition, we discuss the neutron star mass and radius constraints from the terrestrial experiments, using the empirical relations, together with those from the astronomical observations. Furthermore, we find a tight correlation between $η_{τ}$ and $η$ . With this correlation, we derive the constraint on $K_{τ}$ as $- 348 \leq K_{τ} \leq - 237$ MeV, assuming that $L = 60 \pm 20$ and $K_{0} = 240 \pm 20$ MeV.
Comments:
Accepted for publication in RPD. arXiv admin note: text overlap with arXiv:2203.09004
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2210.11651 [pdf]
PRD(2022)·22 citations
02
[Submitted on 21 Oct 2022]
Renormalization of One-Pion Exchange in Higher Partial Waves in Chiral Effective Field Theory for Antinucleon-Nucleon System
Daren Zhou🇨🇳
The renormalization of iterated one-pion exchange (OPE) has been studied in Chiral Effective Field Theory ( $χ$ EFT) for the antinucleon-nucleon ( $N N$ ) scattering in some partial waves (Phys. Rev. C 105, 054005 (2022)). We go further for the other higher partial waves but with total angular momenta $J \leq 3$ in this paper. Contact interactions are represented by a complex spherical well in coordinate space. Changing the radius of the spherical well means changing the cutoff. We check the cutoff dependence of the phase shifts, inelasticities, and mixing angles for the partial waves, and show that contact interactions are needed at leading order in channels where the singular tensor potentials of OPE are attractive. Results are compared with the energy-dependent partial-wave analysis of $N N$ scattering data. Comparisons between our conclusions and applications of $χ$ EFT to the nucleon-nucleon system are discussed as well.
Comments:
26 pages, 3 tables and 13 figures. References are added according to the published version and the related texts are added or modified. arXiv admin note: substantial text overlap with arXiv:2203.06840
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2210.11683 [pdf]
CPC(2023)·0 citations
03
[Submitted on 21 Oct 2022]
Investigating the cluster production mechanism with isospin triggering: Thermal models versus coalescence models
Apiwit Kittiratpattana🇩🇪 · Tom Reichert🇩🇪 · Pengcheng Li🇨🇳 · Ayut Limphirat🇹🇭 · Christoph Herold🇹🇭 · Jan Steinheimer🇩🇪 · Marcus Bleicher🇩🇪
Isospin triggering allows to distinguish coalescence from thermal production of light clusters in heavy ion collisions. Triggering on $Y (π^{-}) - Y (π^{+})$ allows to select very neutron or proton rich final states. The deuteron (cluster) production with coalescence ( $d \propto n \cdot p$ ) leads then to an inverse parabolic dependence of the deuteron yield on $Δ Y_{π}$ . In contrast, in a thermal model, cluster production is independent on $Δ Y_{π}$ . The observation of a maximum deuteron (cluster) yield as function of $Δ Y_{π}$ provides confirmation of the coalescence mechanism.
Comments:
6 pages, 5 figures, version accepted and published by Physical Review C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2210.11699 [pdf]
PRC(2023)·1 citation
04
[Submitted on 21 Oct 2022]
Minimal Length, Nuclear Matter, and Neutron Stars
I. Prasetyo · I. H. Belfaqih · A. B. Wahidin · A. Suroso · A. Sulaksono
In this paper, we employ one variant of the Generalized Uncertainty Principle (GUP) model, i.e., the Kempf-Mangano-Mann (KMM) model, and discuss the impact of GUP on the EoS of nuclear and neutron star matter based on the Relativistic Mean Field (RMF) model. We input the result in the Serrano-Liška (SL) gravity theory to discuss the corresponding Neutron Star (NS) properties. We have shown that the upper bound for the GUP parameter from nuclear matter properties is $β \leq 2 \times 1 0^{- 7}$ MeV $^{- 2}$ . If we used this $β$ upper bound to calculate NS matter, and considering SL parameter $c ~$ as an independent parameter, we have found that the upper bound for the SL parameter, which modifies the Einstein field equation, is $c ~ \leq 1 0^{7}$ m $^{2}$ . This beta upper bound is determined by considering the anisotropy magnitude smaller than the pressure magnitude. By employing $β = 2 \times 1 0^{- 7}$ MeV $^{- 2}$ and $c ~ = 1 0^{7}$ m $^{2}$ , we obtain the mass-radius relation that satisfies NICER data for both PSR J0740+6620 (whose mass is $\sim 2.1 M_{⊙}$ ) and PSR J0030+0451 ( $M \sim 1.4 M_{⊙}$ ). Our GUP parameter upper bound perfectly matches the constraint from $^{87}$ Rb cold-atom-recoil experiment. If we consider that the same strength from the additional logarithmic term in the entropy from both GUP and SL model are dependent, for $β < 2 \times 1 0^{- 7}$ MeV $^{- 2}$ , it is clear that SL parameter lower bound is $c ~ > - 16 \times 1 0^{- 34}$ m $^{2}$ . The magnitude of this bound is $1 0^{- 40}$ smaller than the upper bound magnitude of SL parameter considering as independent parameter i.e., $c ~ \leq 1 0^{7}$ m $^{2}$ .
Comments:
14 pages, 5 figures, published in EPJC
Subjects:
Nuclear Theory (nucl-th); General Relativity and Quantum Cosmology (gr-qc)
arXiv:
2210.11727 [pdf]
EPJC(2022)·16 citations
05
[Submitted on 21 Oct 2022]
Spatial Structure of the $^{12}$ C Nucleus in a 3 $α$ Model with Deep Potentials Containing Forbidden States
E. M. Tursunov · M. Z. Saidov · M. M. Begijonov
The spatial structure of the lowest 0 $_{1}^{+}$ , 0 $_{2}^{+}$ , 2 $_{1}^{+}$ and 2 $_{2}^{+}$ states of the $^{12}$ C nucleus is studied within the 3 $α$ model with the Buck, Friedrich, and Wheatley $α α$ potential with Pauli forbidden states in the $S$ and $D$ waves. The Pauli forbidden states in the three-body system are treated by the exact orthogonalization method. The largest contributions to the ground and excited 2 $_{1}^{+}$ bound states energies come from the partial waves $(λ, ℓ) = (2, 2)$ and $(λ, ℓ) = (4, 4)$ . As was found earlier, these bound states are created by the critical eigenstates of the three-body Pauli projector in the 0 $^{+}$ and 2 $^{+}$ functional spaces, respectively. These special eigenstates of the Pauli projector are responsible for the quantum phase transitions from a weakly bound "gas-like" phase to a deep "quantum liquid" phase. In contrast to the bound states, for the Hoyle resonance 0 $_{2}^{+}$ and its analog state 2 $_{2}^{+}$ , dominant contributions come from the $(λ, ℓ) = (0, 0)$ and $(λ, ℓ) = (2, 2)$ configurations, respectively. The estimated probability density functions for the $^{12}$ C(0 $_{1}^{+}$ ) ground and 2 $_{1}^{+}$ excited bound states show mostly a triangular structure, where the $α$ particles move at a distance of about 2.5 fm from each other. However, the spatial structure of the Hoyle resonance and its analog state have a strongly different structure, like $^{8}$ Be + $α$ . In the Hoyle state, the last $α$ particle moves far from the doublet at the distance between $R = 3.0$ fm and $R = 5.0$ fm. In the Hoyle analog 2 $_{2}^{+}$ state the two alpha particles move at a distance of about 15 fm, but the last $α$ particle can move far from the doublet at the distance up to $R = 30.0$ fm.
Comments:
12 pages, 4 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex); Quantum Physics (quant-ph)
arXiv:
2210.11763 [pdf]
Phys.Atom.Nucl.(2022)·0 citations
06
[Submitted on 21 Oct 2022]
Energy dependence of light hypernuclei production in heavy-ion collisions from a coalescence and statistical-thermal model perspective
Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Volodymyr Vovchenko🇩🇪 · Benjamin Dönigus🇩🇪 · Marcus Bleicher🇩🇪
A comparison of light hypernuclei production, from UrQMD+coalescence and the thermal model, in heavy ion collisions over a wide range of beam energies and system sizes is presented. We find that both approaches provide generally similar results, with differences in specific details. Especially the ratios of hypertriton to $Λ$ are affected by both the source radius $Δ r$ of the coalescence procedure as well as canonical effects. On the other hand, the double ratio $S_{3}$ is almost independent of canonical effects, which is in contrast to coalescence. Thus, both the beam energy dependence and centrality dependence of $S_{3}$ can be used to constrain the hypertriton source radius. To do so the currently available data is not yet sufficient. Elliptic flow is shown to be unaffected by the source size of the nuclei and an almost perfect mass scaling of the elliptic flow is observed. Our predictions further suggest that the existence of the H-dibaryon ( $ΛΛ$ ) seems ruled out by ALICE data.
Comments:
10 pages, 11 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2210.11876 [pdf]
PRC(2023)·33 citations
07
[Submitted on 21 Oct 2022]
The exploration of hot and dense nuclear matter: Introduction to relativistic heavy-ion physics
Hannah Elfner🇩🇪 · Berndt Müller🇺🇸
This article summarizes our present knowledge about nuclear matter at the highest energy densities and its formation in relativistic heavy ion collisions. We review what is known about the structure and properties of the quark-gluon plasma and survey the observables that are used to glean information about it from experimental data.
Comments:
110 pages
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2210.12056 [pdf]
J.Phys.G(2023)·81 citations
08
[Submitted on 21 Oct 2022]
Collective enhancement in the exciton model
M. R. Mumpower🇺🇸 · D. Nuedecker🇺🇸 · H. Sasaki🇺🇸 · T. Kawano🇺🇸 · A. E. Lovell🇺🇸 · M. W. Herman🇺🇸 · I. Stetcu🇺🇸 · M. Dupuis🇫🇷
The pre-equilibrium reaction mechanism is considered in the context of the exciton model. A modification to the one-particle one-hole state density is studied which can be interpreted as a collective enhancement. The magnitude of the collective enhancement is set by simulating the Lawrence Livermore National Laboratory (LLNL) pulsed-spheres neutron-leakage spectra. The impact of the collective enhancement is explored in the context of the highly deformed actinide, 239-Pu. A consequence of this enhancement is the removal of fictitious levels in the Distorted-Wave Born Approximation often used in modern nuclear reaction codes.
Comments:
7 pages, 7 figures. Comments welcome!
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2210.12105 [pdf]
PRC(2023)·5 citations
09
[Submitted on 21 Oct 2022]
Nuclear data activities for medium mass and heavy nuclei at Los Alamos
M. R. Mumpower · T. M Sprouse · T. Kawano · M. W. Herman · A. E. Lovell · G. W. Misch · D. Neudecker · H. Sasaki · I. Stetcu · P. Talou
Nuclear data is critical for many modern applications from stockpile stewardship to cutting edge scientific research. Central to these pursuits is a robust pipeline for nuclear modeling as well as data assimilation and dissemination. We summarize a small portion of the ongoing nuclear data efforts at Los Alamos for medium mass to heavy nuclei. We begin with an overview of the NEXUS framework and show how one of its modules can be used for model parameter optimization using Bayesian techniques. The mathematical framework affords the combination of different measured data in determining model parameters and their associated correlations. It also has the advantage of being able to quantify outliers in data. We exemplify the power of this procedure by highlighting the recently evaluated 239-Pu cross section. We further showcase the success of our tools and pipeline by covering the insight gained from incorporating the latest nuclear modeling and data in astrophysical simulations as part of the Fission In R-process Elements (FIRE) collaboration.
Comments:
6 pages, 5 figures, Nuclear Data (2022) conference proceedings. Comments welcome!
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
arXiv:
2210.12136 [pdf]
EPJ Web Conf.(2023)·2 citations
10
[Submitted on 21 Oct 2022]
Assessing the theory-data tension in neutrino-induced charged pion production: the effect of final-state nucleon distortion
Alexis Nikolakopoulos🇺🇸 · Raúl González-Jiménez🇪🇸 · Natalie Jachowicz🇧🇪 · José Manuel Udías🇪🇸
Pion production on nuclei constitutes a significant part of the total cross section in experiments involving few-GeV neutrinos. Combined analyses of data on deuterium and heavier nuclei points to tensions between the bubble chamber data and the data of the MINER $ν$ A experiment, which are often ascribed to unspecified nuclear effects. To understand the origin of these tensions, a microscopic quantum mechanical framework is needed to compute nuclear matrix elements. We use the local approximation to the relativistic distorted wave impulse approximation (RDWIA) to assess the role of final-state nucleon distortion. To perform this comparison under conditions relevant to neutrino experiments, we compute cross sections for the MINER $ν$ A and T2K charged pion production datasets. The inclusion of nucleon distortion leads to a reduction of the cross section up to 10\%, but to no significant change in shape of the flux-averaged cross sections. Results with and without distortion compare favorably to experimental data, with the exception of the low- $Q^{2}$ MINER $ν$ A $π^{+}$ data. We point out that hydrogen target data from BEBC is also overpredicted at low- $Q^{2}$ , and that the discrepancy is similar in shape and magnitude to what is found in comparison to MINER $ν$ A data. Including nucleon distortion alone cannot explain the overprediction of low- $Q^{2}$ cross sections measured by MINER $ν$ A. The similar overprediction of BEBC data on hydrogen means that it is impossible to ascribe this discrepancy solely to a nuclear effect. Axial couplings and their $Q^{2}$ dependence should ideally be derived from more precise data on hydrogen and deuterium.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2210.12144 [pdf]
PRD(2023)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE