Nuclear Theory·nucl-th

Friday·June 9, 2023

10 papers—8 primary·2 cross-listed

01
Momentum-space second-order pion-nucleus potential including medium effects in the $Δ (1232)$ region
Viacheslav Tsaran🇩🇪 · Marc Vanderhaeghen🇩🇪
In this work, we develop an updated model for pion-nucleus scattering in the framework of the distorted wave impulse approximation in momentum space. We construct the second-order pion-nucleus potential, which involves analysis of pion-nucleus elastic scattering as a solution of the Lippmann-Schwinger equation. The potential is based on the individual pion-nucleon scattering amplitudes extracted from SAID, and its second-order correction is presented in detail. We estimate optimal energy-independent parameters of the potential by a multi-energy fit of the pion- $^{12}$ C total, reaction, and differential elastic cross sections. We show the predictive power by applying it to pion elastic scattering on $^{16}$ O, $^{28}$ Si, and $^{40}$ Ca.
nucl-thhep-phPRC(2023)·4 citations
02
Spin entanglement in neutron-proton scattering
Dong Bai
In this Letter, I work out spin entanglement properties of neutron-proton scattering using the exact S-matrix, generalizing previous works based on S wave. The dependence of spin entanglement on momentum, scattering angle, and initial spin configuration is investigated for realistic nuclear forces, while low-energy properties of spin entanglement are analyzed within the framework of pionless effective field theory at leading order. New connections are found between spin entanglement and symmetry enhancement of strong interactions. These results lead to a more complete understanding of how spin entanglement is generated via neutron-proton interaction. They also lay the theoretical foundation for controllable production of entangled nucleon-nucleon pairs in future experiments.
nucl-thPLB(2023)·31 citations
03
The hadronic equation of state of HESS J1731-347 from the relativistic mean-field model with tensor coupling
Kaixuan Huang · Jinniu Hu · Ying Zhang · Hong Shen
A recent report has identified a central compact object (CCO) within the supernova remnant HESS J1731-347, with a mass and radius of $M = 0.7 7_{- 0.17}^{+ 0.20} M ⊙$ and $R = 10. 4_{- 0.78}^{+ 0.86}$ km, respectively. To investigate this light compact star, a density-dependent relativistic mean-field (DDRMF) model, specifically the DDVT model, has been employed. The DDVT model incorporates tensor couplings of vector mesons, which {can} successfully describe the properties of finite nuclei, such as charge radius, binding energy, and spin-orbit splitting. The introduction of tensor coupling reduces the influence of scalar mesons and generates a softer equation of state (EOS) in the outer core of the neutron star. Moreover, it has been found that the crust segment plays a crucial role in reproducing the mass-radius relation of HESS J1731-347, indicating a preference for a soft crust EOS. By manipulating the coupling strength of the isovector meson in the DDVT parameter set, a reasonable hadronic EOS has been obtained, satisfying the constraints from the gravitational-wave signal GW170817, the simultaneous mass-radius measurements from the NICER collaboration, and the properties of finite nuclei. Notably, the mass-radius relations derived from this hadronic EOS also accurately describe the observables of HESS J1731-347. Therefore, based on our estimation, the CCO in HESS J1731-347 may represent the lightest known neutron star.
nucl-thastro-ph.HEPRD(2024)·21 citations
04
Observational constraint from the heaviest pulsar PSR J0952-0607 on the equation of state of dense matter in relativistic mean field model
Raj Kumar · Mukul Kumar · Virender Thakur · Sunil Kumar · Pankaj Kumar · Anuj Sharma · B.K. Agrawal · Shashi K. Dhiman
In the present work, we constrain the equation of the state of dense matter in the context of heaviest observed neutron star mass M $_{ma x}$ = 2.35 $\pm 0.17$ M $_{⊙}$ for the black widow pulsar PSR J0952-0607. We propose three interactions HPU1, HPU2 and HPU3 (named after Himachal Pradesh University)for the relativistic mean field model which include different combinations of non-linear, self and cross-couplings among isoscalar-scalar $σ$ , isoscalar-vector $ω$ and isovector-vector $ρ$ meson fields up to the quartic order. These interactions are in harmony with the finite nuclei and bulk nuclear matter properties. The equations of state computed by using newly generated interactions for the $β$ -equilibrated nucleonic matter satisfy the heaviest observed neutron star mass M $_{ma x}$ = 2.35 $\pm 0.17$ M $_{⊙}$ for the black widow pulsar PSR J0952-0607. The results for the radius ( $R_{1.4}$ ) and dimensionless tidal deformability ( $Λ_{1.4}$ ) corresponding to the canonical mass are also presented and agree well with the GW170817 event and astrophysical observations. The radius of $2.08 M_{⊙}$ neutron star mass is predicted to be in the range $R_{2.08}$ = 12.98 -13.09 Km which also satisfies the NICER observations by Miller et al. (2021) and Riley et al.(2021). A covariance analysis is also performed to assess the theoretical uncertainties of model parameters and to determine their correlations with nuclear matter observables.
nucl-thPRC(2023)·28 citations
05
Relativistic Mean Field Model parameterizations in the light of GW170817, GW190814, and PSR J0740 + 6620
Virender Thakur🇮🇳 · Raj Kumar🇮🇳 · Pankaj Kumar🇮🇳 · Vikesh Kumar🇮🇳 · B. K. Agrawal🇮🇳 · Shashi K. Dhiman🇮🇳
Three parameterizations DOPS1, DOPS2, and DOPS3 (named after the Department of Physics Shimla) of the Relativistic Mean Field (RMF) model have been proposed with the inclusion of all possible self and mixed interactions between the scalar-isoscalar (\sigma), vector-isoscalar (\omega) and vector-isovector (\rho) mesons up to quartic order. The generated parameter sets are in harmony with the finite and bulk nuclear matter properties. A set of Equations of State (EOSs) composed of pure hadronic (nucleonic) matter and nucleonic with quark matter (hybrid EOSs) for superdense hadron-quark matter in \beta-equilibrium is obtained. The quark matter phase is calculated by using the three-flavor Nambu-Jona-Lasinio (NJL) model. The maximum mass of a non-rotating neutron star with DOPS1 parameterization is found to be around 2.6 M $⊙$ for the pure nucleonic matter which satisfies the recent gravitational wave analysis of GW190814 Abbott et al.,(2020) with possible maximum mass constraint indicating that the secondary component of GW190814 could be a non-rotating heaviest neutron star composed of pure nucleonic matter. EOSs computed with the DOPS2 and DOPS3 parameterizations satisfy the X-Ray observational data and the recent observations of GW170817 maximum mass constraint of a stable non-rotating neutron star in the range 2.01 \pm 0.04 - 2.16 \pm 0.03 M\odot and also in good agreement with constraints on mass and radius measurement for PSR J0740+6620 (NICER) Riley et al., L27 (2021)}, Miller et al., (2021). The hybrid EOSs obtained with the NJL model also satisfy astrophysical constraints on the maximum mass of a neutron star from PSR J1614-2230 and Demorest et al., (2010) .We also present the results for dimensionless tidal deformability, $Λ$ which are consistent with the waveform models analysis of GW170817.
nucl-thPRC(2022)·31 citations
06
Description of the proton-decaying 0 $_{2}^{+}$ resonance of the $α$ particle
N. Michel🇨🇳 · W. Nazarewicz🇺🇸 · M. Płoszajczak🇫🇷
The recent precise experimental determination of the monopole transition form factor from the ground state of $^{4}$ He to its $0_{2}^{+}$ resonance via electron scattering has reinvigorated discussions about the nature of this first excited state of the $α$ particle. The $0_{2}^{+}$ state has been traditionally interpreted in the literature as the isoscalar monopole resonance (breathing mode) or, alternatively, as a particle-hole shell-model excitation. To better understand the nature of this state, which lies only $\sim$ 410 keV above the proton emission threshold, we employ the coupled-channel representation of the no-core Gamow shell model. By considering the $[^{3}$ H $+ p]$ , $[^{3}$ He $+ n]$ , and $[^{2}$ H+ $^{2}$ H] reaction channels, we explain the excitation energy and monopole form-factor of the $0_{2}^{+}$ state. We argue that the continuum coupling strongly impacts the nature of this state, which carries characteristics of the proton decay threshold.
nucl-thPRL(2023)·27 citations
07
Description of $^{7}$ Be and $^{7}$ Li within the Gamow Shell Model
J.P. Linares Fernandez🇫🇷 · N. Michel🇨🇳 · M. Płoszajczak🇫🇷 · A. Mercenne🇺🇸
$^{7}$ Li and $^{7}$ Be play an important role in Big Bang nucleosynthesis and nuclear astrophysics. The $^{3}$ H( $^{4}$ He, $γ$ ) $^{7}$ Li radiative capture reaction is crucial for the determination of the primordial $^{7}$ Li abundance. In nuclear astrophysics, lithium isotopes have attracted a great interest because of the puzzled abundance of $^{6}$ Li and $^{7}$ Li. Purpose: In this work we study spectra of $^{7}$ Be, $^{7}$ Li and elastic scattering cross sections $^{4}$ He( $^{3}$ He, $^{3}$ He), $^{4}$ He( $^{3}$ H, $^{3}$ H) within the Gamow shell model (GSM) in the coupled-channel formulation (GSM-CC). The evolution of channel amplitudes and spectroscopic factors in the vicinity of the channel threshold is studied for selected states. Methods: GSM provides the open quantum system formulation of nuclear shell model. In the representation of GSM-CC, GSM provides the unified theory of nuclear structure and reactions which is suited for the study of resonances in $^{7}$ Be, $^{7}$ Li and elastic scattering cross-sections involving $^{3}$ H and $^{3}$ He projectiles. Results: The GSM-CC in multi-mass partition formulation applied to a translationally invariant Hamiltonian with an effective finite-range two-body interaction reproduce well the spectra of $^{7}$ Be, $^{7}$ Li and elastic scattering reactions: $^{4}$ He( $^{3}$ He, $^{3}$ He), $^{4}$ He( $^{3}$ H, $^{3}$ H). Detailed analysis of the dependence of reaction channel amplitudes and spectroscopic factors on the distance from the particle decay threshold allowed to demonstrate the alignment of the wave function in the vicinity of the decay threshold. This analysis also demonstrates the appearance of clustering in the GSM-CC wave function in the vicinity of the cluster decay threshold.
nucl-thPRC(2023)·20 citations
08
Chiral EFT calculation of neutrino reactions in warm neutron-rich matter
Eunkyoung Shin🇺🇸 · Ermal Rrapaj🇺🇸 · Jeremy W. Holt🇺🇸 · Sanjay K. Reddy🇺🇸
Neutrino scattering and absorption rates of relevance to supernovae and neutron star mergers are obtained from nuclear matter dynamical structure functions that encode many-body effects from nuclear mean fields and correlations. We employ nuclear interactions from chiral effective field theory to calculate the density, spin, isospin, and spin-isospin response functions of warm beta-equilibrium nuclear matter. We include corrections to the single-particle energies in the mean field approximation as well as vertex corrections resummed in the random phase approximation (RPA), including, for the first time, both direct and exchange diagrams. We find that correlations included through the RPA redistribute the strength of the response to higher energy for neutrino absorption and lower energy for antineutrino absorption. This tends to suppress the absorption rate of electron neutrinos across all relevant energy scales. In contrast, the inclusion of RPA correlations enhances the electron antineutrino absorption rate at low energy and supresses the rate at high energy. These effects are especially important at high-density and in the vicinity of the neutrino decoupling region. Implications for heavy element nucleosynthesis, electromagnetic signatures of compact object mergers, supernova dynamics, and neutrino detection from galactic supernovae are discussed briefly.
nucl-thastro-ph.HEhep-phPRC(2024)·12 citations
09
Signals of strong parity violation in deep inelastic scattering
Alessandro Bacchetta🇮🇹 · Matteo Cerutti🇮🇹 · Ludovico Manna🇮🇹 · Marco Radici🇮🇹 · Xiaochao Zheng🇺🇸
We include strong parity-violating contributions to inclusive deep inelastic scattering (DIS) of longitudinally polarized leptons off an unpolarized target. At variance with standard results, we obtain nonvanishing parity-violating structure functions in the case of pure photon exchange. The addition of these strong parity-violating contributions improves the description of existing experimental data on DIS parity-violating asymmetries. We find the size of these contributions small but exhibiting a deviation from zero of about 1.5 $σ$ . The associated $p$ -value is 0.063, indicating that the probability of making an error by rejecting the hypothesis of no parity-violating contributions is 6.3\%, which is small but not negligible. Further improvement on the limit of the strong parity-violation can be expected from the future SoLID program at Jefferson Lab.
↳ hep-phhep-exnucl-exnucl-thPLB(2024)·9 citations
10
The 3+1D initialization and evolution of the Glasma
Scott McDonald🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
The IP-Glasma initial condition has been highly successful in the phenomenology of ultra-relativistic heavy ion collisions. The assumption of boost invariance, however, while good for collision energies probed at the LHC, limits the use of IP-Glasma to the transverse dynamics of heavy ion collision to near mid-rapidity. There is a wealth of physics to be explored and understood in the longitudinal dynamics of heavy ion collisions, and a full understanding of heavy ion collisions can only come from 3-dimensional studies. In particular, long range rapidity correlations are seeded in the initial collision and provide additional information on the high energy nuclear wave functions that has thus far been inaccessible to the IP-Glasma model. In this work, we introduce a way to extend the IP-Glasma model to 3+1-dimensions while preserving its key features.
↳ hep-phnucl-thPRC(2023)·34 citations

Affiliations

first authorsco-authorsvia INSPIRE