Nuclear Theory·nucl-th

Monday·June 7, 2021

7 papers—5 primary·2 cross-listed

01
Charge radii of potassium isotopes in the RMF(BCS)* approach
Rong An · Shi-sheng Zhang · Li-sheng Geng · Feng-shou Zhang
We apply the recently proposed RMF(BCS)* ansatz to study the charge radii of the potassium isotopic chain up to $^{52}$ K. It is shown that the experimental data can be reproduced rather well, qualitatively similar to the Fayans nuclear density functional theory, but with a slightly better description of the odd-even staggerings (OES). Nonetheless, both methods fail for $^{50}$ K and to a lesser extent for $^{48, 52}$ K. It is shown that if these nuclei are deformed with a $β_{20} \approx - 0.2$ , then one can obtain results consistent with experiments for both charge radii and spin-parities. We argue that beyond mean field studies are needed to properly describe the charge radii of these three nuclei, particularly for $^{50}$ K.
nucl-thCPC(2022)·16 citations
02
Theoretical description of semi-inclusive T2K, Miner $ν$ A and MicroBooNE neutrino-nucleus data in the relativistic plane wave impulse approximation
J. M. Franco-Patino🇪🇸 · M. B. Barbaro🇮🇹 · J. A. Caballero🇪🇸 · G. D. Megias🇪🇸
We present the results of semi-inclusive neutrino-nucleus cross sections within the plane wave impulse approximation (PWIA) for three nuclear models: relativistic Fermi gas (RFG), independent-particle shell model (IPSM) and natural orbital shell model (NO) in comparison with the available CC0 $π$ measurements from the T2K, MINER $ν$ A and MicroBooNE collaborations where a muon and at least one proton are detected in the final state. Results are presented as a function of the momenta and angles of the final particles, as well as in terms of the imbalances between proton and muon kinematics. The analysis reveals that contributions beyond PWIA are crucial to explain the experimental measurements and that the study of correlations between final-state proton and muon kinematics can provide valuable information on relevant nuclear effects such as the Fermi motion and final state interactions.
nucl-thPRD(2021)·16 citations
03
Systematic study of near yrast band structures in odd-mass $^{125 - 137}$ Pr and $^{127 - 139}$ Pm isotopes
S. Jehangir · G.H. Bhat · N. Rather · J.A. Sheikh · R. Palit
In the present work, the basis space in the triaxial projected shell model approach is expanded to include three and five quasiparticle configurations for odd-proton systems. This extension allows to investigate the high-spin band structures observed in odd-proton systems up to and including the second band crossing region, and as a first major application of this development, the high-spin properties are investigated for odd-mass $^{125 - 137}$ Pr and $^{127 - 139}$ Pm isotopes. It is shown that band crossings in the studied isotopes have mixed structures with first crossing dominated by one-proton coupled to two-neutron configuration for the lighter isotopes which then changes to three-proton configuration with increasing neutron number. Further, $γ$ -bands based on quasiparticle states are also delineated in the present work, and it is predicted that these band structures built on three-quasiparticle configurations become favoured in energy for heavier systems in the high-spin region.
nucl-thnucl-exPRC(2021)·16 citations
04
Impact of Multiplicity Fluctuations on Entropy Scaling Across System Size
Patrick Carzon🇺🇸 · Matthew D. Sievert🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸
The initial state is one of the greatest uncertainties in heavy-ion collisions. A model-agnostic approach is taken in the phenomenological Trento framework which constrains parameters using Bayesian analysis. However, the color-glass condensate (CGC) effective theory predicts initial energy densities that lie outside the recent Bayesian analyses due, in part, to the assumption in Trento of event-by-event multiplicity fluctuations following a $Γ$ distribution. We compare the Trento-preferred $T_{A} T_{B}$ scaling to CGC-like $T_{A} T_{B}$ scaling coupled with log-normal fluctuations in $A u A u$ and $d A u$ collisions and find there is a significant impact on the multiplicity distributions and on the eccentricities, which may affect the extraction of viscosity in small systems.
nucl-thhep-phnucl-exPRC(2022)·6 citations
05
Uncertainties in the $^{18}$ F(p, $α$ ) $^{15}$ O reaction rate in classical novae
D. Kahl · J. José · P.J. Woods
Context. Direct observation of gamma-ray emission from the decay of $^{18}$ F ejected in classical nova outbursts remains a major focus of the nuclear astrophysics community. However, modeling the abundance of ejected $^{18}$ F, and thus the predicted detectability distance of a gamma-ray signal near 511 keV emitted from these transient thermonuclear episodes, is hampered by significant uncertainties in our knowledge of the key $^{18}$ F(p, $α$ ) reaction rate. Aims. We analyze uncertainties in the most recent nuclear physics experimental results employed to calculate the $^{18}$ F(p, $α$ ) reaction rate. Our goal is to determine which uncertainties have the most profound influence on the predicted abundance of $^{18}$ F ejected from novae, in order to guide future experimental works. Methods. We calculated a wide range of $^{18}$ F(p, $α$ ) reaction rates using R-Matrix formalism, allowing us to take into account all interference effects. Using a selection of 16 evenly-spaced rates over the full range, we performed 16 new hydrodynamic nova simulations. Results. We performed one of the most thorough theoretical studies of the impact of the $^{18}$ F(p, $α$ ) reaction in classical novae to date. The $^{18}$ F(p, $α$ ) rate remains highly uncertain at nova temperatures, resulting in a factor ~10 uncertainty in the predicted abundance of $^{18}$ F ejected from nova explosions. We also found that the abundance of $^{18}$ F may be strongly correlated with that of $^{19}$ F. Conclusions. Despite numerous nuclear physics uncertainties affecting the $^{18}$ F(p, $α$ ) reaction rate, which are dominated by unknown interference signs between 1/2 $^{+}$ and 3/2 $^{+}$ resonances, future experimental work should focus on firmly and precisely determining the directly measurable quantum properties of the subthreshold states in the compound nucleus $^{19}$ Ne near 6.13 and 6.29 MeV.
nucl-thastro-ph.HEastro-ph.SRAstron.Astrophys.(2021)·11 citations
06
Neutron stars in $f (R, L_{m})$ gravity with realistic equations of state: joint-constrains with GW170817, massive pulsars, and the PSR J0030+0451 mass-radius from $NICER$ data
R. V. Lobato · G. A. Carvalho · C. A. Bertulani
In this work we investigate neutron stars (NS) in $f (R, L_{m})$ theory of gravity for the case $f (R, L_{m}) = R + L_{m} + σ R L_{m}$ , where $R$ is the Ricci scalar and $L_{m}$ the Lagrangian matter density. In the term $σ R L_{m}$ , $σ$ represents the coupling between the gravitational and particles fields. For the first time the hydrostatic equilibrium equations in the theory are solved considering realistic equations of state and NS masses and radii obtained are subject to joint constrains from massive pulsars, the gravitational wave event GW170817 and from the PSR J0030+0451 mass-radius from NASA's Neutron Star Interior Composition Explorer ( $NICER$ ) data. We show that in this theory of gravity, the mass-radius results can accommodate massive pulsars, while the general theory of relativity can hardly do it. The theory also can explain the observed NS within the radius region constrained by the GW170817 and PSR J0030+0451 observations for masses around $1.4 M_{⊙}$ .
↳ gr-qcastro-ph.HEnucl-thEPJC(2021)·62 citations
07
Effective Matrix Model for Gauge Theories at Finite Temperature and Density using Quantum Computing
Yuan Feng🇺🇸 · Michael McGuigan🇺🇸
We study the effective matrix model for for gauge fields and fermions on a quantum computer. We use the Variational Quantum Eigensolver (VQE) using IBM QISKit for the effective matrix model for SU(2) and SU(3) including fermions in the fundamental representation. For SU(2) we study the effects of finite temperature and nonzero chemical potential. In all cases we find excellent agreement with the classical computation.
↳ quant-phhep-thnucl-th2 citations

Affiliations

first authorsco-authorsvia INSPIRE

Charge radii of potassium isotopes in the RMF(BCS)* approach

Theoretical description of semi-inclusive T2K, MinerνA and MicroBooNE neutrino-nucleus data in the relativistic plane wave impulse approximation

Systematic study of near yrast band structures in odd-mass 125−137Pr and 127−139Pm isotopes

Impact of Multiplicity Fluctuations on Entropy Scaling Across System Size

Uncertainties in the 18F(p,α)15O reaction rate in classical novae

Neutron stars in f(R,Lm​) gravity with realistic equations of state: joint-constrains with GW170817, massive pulsars, and the PSR J0030+0451 mass-radius from NICER data

Effective Matrix Model for Gauge Theories at Finite Temperature and Density using Quantum Computing

Affiliations

Theoretical description of semi-inclusive T2K, Miner $ν$ A and MicroBooNE neutrino-nucleus data in the relativistic plane wave impulse approximation

Systematic study of near yrast band structures in odd-mass $^{125 - 137}$ Pr and $^{127 - 139}$ Pm isotopes

Uncertainties in the $^{18}$ F(p, $α$ ) $^{15}$ O reaction rate in classical novae

Neutron stars in $f (R, L_{m})$ gravity with realistic equations of state: joint-constrains with GW170817, massive pulsars, and the PSR J0030+0451 mass-radius from $NICER$ data