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Nuclear Theory·nucl-th

Tuesday·October 18, 2022

17 papers—9 primary·8 cross-listed

All17Primary9Cross-lists8
  1. 01

    Intense X-ray laser-induced proton emission from halo nuclei

    Binbing Wu · Jie Liu

    We investigate the intense X-ray laser-induced proton emission from halo nuclei within the framework of a nonperturbative quantum -matrix approach. We have analytically deduced the angular differential as well as the total multi-photon rates of the proton emissions. For a linearly polarized X-ray laser field, we find that the angular distributions of proton emission sensitively depend on the laser frequency and show an interesting petal structure with increasing the laser frequency as well as the number of absorbed photons. Meanwhile, we find the Coulomb repulsion potential between the proton and the remainder nucleus has a strong hindering effect on the total multi-photon rates of the proton emissions and leads to the blue shifts of the multi-photon transition frequency. Moreover, the polarization effects of laser fields on total rates of proton emission have also been addressed. We find that the polarized ellipticity corresponding to the maximum of the total rates depend on the laser frequency showing a transition from perturbative to nonperturbative proton emission. The underlying mechanism of the above findings is uncovered, and some implications are discussed.

    nucl-thPRC(2022)·3 citations
  2. 02

    Elliptic flow in heavy-ion collisions at intermediate energy: the role of impact parameter, mean field potential, and collision term

    Bo Gao🇨🇳 · Yongjia Wang🇨🇳 · Zepeng Gao🇨🇳 · Qingfeng Li🇨🇳

    Within the ultrarelativistic quantum molecular dynamics (UrQMD) model, by reverse tracing nucleons that are finally emitted at mid-rapidity (|| < 0.1) in the entire reaction process, the time evolution of elliptic flow () of these traced nucleons produced in Au+Au collisions at beam energy of 0.4 GeVnucleon with different impact parameters () is studied. The initial value of is positive and increases with , then it decreases as time passes and tends to saturate at a negative value. It is found that nucleon-nucleon collisions always depress the value of (enhance the out-of-plane emission), while the nuclear mean field potential may slightly raise the value of during the expansion stage in peripheral reactions. The related density mostly probed by of nucleons at mid-rapidity is found to be 60% of the maximum density reached during the collisions.

    nucl-thPLB(2023)·14 citations
  3. 03

    ARIEL experiments and theory

    Petr Navratil🇨🇦

    I present an overview of experiments at TRIUMF ARIEL and ISAC facilities covering both the current and the future envisioned programs. I also briefly review theory program at TRIUMF that relates to the ARIEL experimental program. I highlight several recent experimental results from the nuclear astrophysics, nuclear structure, fundamental symmetries, and the sterile neutrino search. Finally, I mention ongoing theoretical ab initio calculations of the proton capture on 7Li related to the X17 boson observation.

    nucl-thnucl-exJ.Phys.Conf.Ser.(2022)·4 citations
  4. 04

    Constraints on the nuclear Schiff moment from its correlation with electromagnetic properties

    K. Yanase · N. Shimizu · K. Higashiyama · N. Yoshinaga

    We study the nuclear Schiff moments of Xe and Hg induced by the nucleon electric dipole moment using large-scale shell model calculations. For Xe, we find a linear relation between the leading-order contribution and magnetic moment, which would be useful in reducing the theoretical uncertainty. The conventional model space does not contain the and orbitals, which are connected to the spin-orbit partners by large matrix elements. Thus, to evaluate the influence of the relevant single-particle orbitals outside the conventional model space, we apply the quasiparticle vacua shell model method. Moreover, the next-to-leading-order contribution arises from parity and time-reversal violation inside the nucleus. We demonstrate that these secondary effects do not induce any significant disturbance to the correlation. Additionally, we report the shell model results for the nuclear Schiff moment coefficients of Hg. Compared to previous studies, the results obtained in this study are rather large, indicating a higher sensitivity to the neutron electric dipole moment.

    nucl-thhep-exhep-phnucl-exPLB(2023)·10 citations
  5. 05

    Multi-Neutrino Entanglement and Correlations in Dense Neutrino Systems

    Marc Illa🇺🇸 · Martin J. Savage🇺🇸

    The time-evolution of multi-neutrino entanglement and correlations are studied in two-flavor collective neutrino oscillations, relevant for dense neutrino environments, building upon previous works. Specifically, simulations performed of systems with up to 12 neutrinos using Quantinuum's H1-1 20 qubit trapped-ion quantum computer are used to compute n-tangles, and two- and three-body correlations, probing beyond mean-field descriptions. n-tangle re-scalings are found to converge for large system sizes, signaling the presence of genuine multi-neutrino entanglement.

    nucl-thhep-phquant-phPRL(2023)·58 citations
  6. 06

    Application of R-matrix and Lagrange-mesh methods to nuclear transfer reactions

    Shubhchintak · P. Descouvemont

    Background: Nuclear transfer reactions are a useful tool to study the structure of a nucleus. For reactions involving weekly bound nuclei, breakup effects can play significant role and theoretical calculations can be computational expensive in such cases. Purpose: To utilize the Lagrange-mesh and R-matrix methods for nuclear transfer reactions. Methods: We use the adiabatic distorted wave approximation (ADWA) method which can approximately treats the breakup effects in a simpler manner. In our approach, we apply the R-matrix method combining it with the Lagrange-mesh method, which is known to provide the fast and accurate computations. Results: As a test case, we calculate the angular distribution of the cross sections for the 54Fe(d, p)55Fe reaction, where deuteron breakup effects play important role. Conclusions: We show that these methods work well in the ADWA framework, and we look forward to applying these methods in coupled channel calculations.

    nucl-thnucl-exJ. Nucl. Phys. Mat. Sci. Rad. A. Vol. 9, …·0 citations
  7. 07

    Ab initio single-neutron spectroscopic overlaps in lithium isotopes

    G. H. Sargsyan · K. D. Launey · R. M. Shaffer · S. T. Marley · N. Dudeck · A. Mercenne · T. Dytrych · J. P. Draayer

    We calculate single-neutron spectroscopic overlaps for lithium isotopes in the framework of the \textit{ab initio} symmetry-adapted no-core shell model. We report the associated neutron-nucleus asymptotic normalization coefficients (ANCs) and spectroscopic factors (SFs) that are important ingredients in many reaction cross section calculations. While spectroscopic factors have been traditionally extracted from experimental cross sections, their sensitivity on the type of reactions, energy, and the underlying models point to the need for determining SF from first-principle structure considerations. As illustrative examples, we present Li+n, Li+n, and Li+n, and we show that the results are in a good agreement with those of other \textit{ab initio} methods, where available, including the quantum Monte Carlo approach. We compare ANCs and SFs to available experimentally deduced values, with a view toward expanding this study to heavier nuclei and to extracting inter-cluster effective interactions for input into analyses of existing and future experimental data.

    nucl-thnucl-exPRC(2023)·9 citations
  8. 08

    Prediction for the synthesis cross sections of new moscovium isotopes in fusion-evaporation reactions

    Peng-Hui Chen · Hao Wu · Zu-Xing Yang · Xiang-Hua Zeng · Zhao-Qing Feng

    In the framework of the dinuclear system model, the synthesis mechanism of the superheavy nuclides with atomic number in the reactions of projectiles Ca bombarding on targets U, Pu, and Am at a wide incident energies (excitation energy from 0-100 MeV) have been investigated systematically. Based on the available experimental excitation functions, the dependence of calculated synthesis cross sections on collision orientations has been studied thoroughly. The TKEs of these collisions with the fixed collision orientation show its orientation dependence which can be used to predict the tendency of kinetic energy diffusion. The TKEs are dependent on incident energies which have been discussed. The method of Coulomb barrier distribution function has been applied in our calculations which could treat all of the collision orientations from the tip-tip to side-side approximately. The calculations of excitation functions of Ca + U, Ca + Pu, and Ca + Am have a nice agreement with the available experimental data. The isospin effect of projectiles on production cross sections of moscovium isotopes and the influence of entrance channel effect on the synthesis cross sections of superheavy nuclei have been discussed. The synthesis cross section of new moscovium isotopes Mc have been predicted as large as hundreds pb, in the fusion-evaporation reactions of Cl + Cf, Ar + Bk, K + Cm, Ca + Am, Sc + Pu, and Ti + Np, V + U at the excitation energy interval of 0-100 MeV.

    nucl-thNucl.Sci.Tech.(2023)·15 citations
  9. 09

    Multinucleon transfer mechanism in

    S. Ayik · M. Arik · O. Yilmaz · B. Yilmaz · A. S. Umar

    Production cross-sections of heavy neutron-rich isotopes are calculated by employing quantal transport description in collisions. This quantal transport description is based on the stochastic mean-field (SMF) approach, and it provides a microscopic approach beyond time-dependent Hartree-Fock (TDHF) theory to include mean-field fluctuations. De-excitation of primary fragments is determined by employing the statistical GEMINI++ code. Calculations provide predictions for production cross-sections of neutron rich transfermium isotopes without any adjustable parameters.

    nucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE