PaperPanorama
FAQ

Nuclear Theory·nucl-th

Tuesday·March 12, 2024

16 papers—6 primary·10 cross-listed

All16Primary6Cross-lists10
  1. 01

    [Submitted on 9 Mar 2024]

    Muon Capture on Li, C, and O from Nuclear Theory

    Lotta Jokiniemi🇨🇦 · Petr Navratil🇨🇦 · Jenni Kotila🇫🇮 · Kostas Kravvaris🇺🇸

    Muon capture on nuclei is one of the most promising probes of the nuclear electroweak current driving the yet-hypothetical neutrinoless double-beta () decay. Both processes involve vector and axial-vector currents at finite momentum transfer, MeV, as well as the induced pseudoscalar and weak-magnetism currents. Comparing measured muon-capture rates with reliable nuclear-theory predictions could help us validate these currents. To this end, we compute partial muon-capture rates for Li, C and O, feeding the ground and excited states in He, B and N, using no-core shell model with two- and three-nucleon chiral interactions. We remove the spurious center-of-mass motion by introducing translationally invariant operators and approximate the effect of hadronic two-body currents by Fermi-gas model. We solve the bound-muon wave function from the Dirac wave equations in the Coulomb field created by a finite nucleus. We find that the computed rates to the low-lying states in the final nuclei are in good agreement with the measured counterparts. We highlight sensitivity of some of the transitions to the sub-leading three-nucleon interaction terms. We also compare summed rates to several tens of final states with the measured total capture rates and note that we slightly underestimate the total rate with this simple approach due to limited range of excitation energies.

    Comments:
    15 pages, 11 figures, 5 tables; corresponds to the published version
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2403.05776 [pdf]
    PRC(2024)·17 citations
  2. 02

    [Submitted on 9 Mar 2024]

    Description of moment of inertia and the interplay between anti-pairing and pairing correlations in even-even Pu and Cm

    Anshul Dadwal · Xiao-Tao He

    Within the supersymmetry scheme, which includes many-body interactions and a perturbation possessing the SO(5) (or SU(5)) symmetry, the rotational bands of the mass region are studied systematically. A novel modification is introduced, extending the Arima coefficient to the third order. This study is dedicated to the quantitative analysis of evolving trends in intraband -transition energy, kinematic, and the dynamic moment of inertia within the rotational bands of Pu and Cm. The computed outcomes exhibit an exceptional degree of agreement with experimental observations across various conditions. The significance of including a higher-order Arima coefficient is further examined by contrasting it with the previously suggested model. The calculated results demonstrate the significance of both the anti-pairing and pairing effects in the evolution of the dynamic moment of inertia. Additionally, these insights reveal the importance of a newly introduced parameter in accurately depicting complex nuclear behaviors such as back-bending, up-bending, and the downturn in the moment of inertia.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.05823 [pdf]
    CPC(2024)·1 citation
  3. 03

    [Submitted on 9 Mar 2024]

    Neutron scattering off spherical nuclei with global nonlocal dispersive optical model

    B. Morillon · G. Blanchon · P. Romain · H.F. Arellano

    We present a global nonlocal and dispersive optical model potential for neutron scattering off spherical nuclei with incident energies up to 250 MeV. This optical model is an extension of the non-dispersive Perey-Buck potential. The imaginary components are chosen energy-dependent and the dispersive constraints are taken into account. The surface imaginary part is nonlocal, whereas the volume imaginary part above 10 MeV is local, allowing to reproduce total cross sections and scattering data for high energies. We obtain a good description of scattering observables for target-nuclei ranging from , up to . The inclusion of nonlocal spin-orbit term enables a better description of the analyzing power data relative to the local dispersive model.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.05843 [pdf]
    PRC(2024)·5 citations
  4. 04

    [Submitted on 10 Mar 2024]

    Accessing the speed of sound in relativistic ultracentral nucleus-nucleus collisions using the mean transverse momentum

    Fernando G. Gardim🇧🇷 · Andre V. Giannini🇧🇷 · Jean-Yves Ollitrault🇫🇷

    It has been argued that the speed of sound of the strong interaction at high temperature can be measured using the variation of the mean transverse momentum with the particle multiplicity in ultracentral heavy-ion collisions. We test this correspondence by running hydrodynamic simulations at zero impact parameter with several equations of state, at several colliding energies from 0.2 TeV to 15 TeV per nucleon pair. The correspondence is found to be precise and robust for a smooth, boost-invariant fluid and an ideal detector. We discuss the differences between this ideal setup and an actual experiment. We conclude that the extraction of the speed of sound from data is reliable, and that the main uncertainty comes from our poor knowledge of the distribution of density fluctuations at the early stages of the collision.

    Comments:
    v2: 8 pages, 4 figures. Added new section IV - E. Matches the published version
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2403.06052 [pdf]
    PLB(2024)·21 citations
  5. 05

    [Submitted on 10 Mar 2024]

    Investigating meson production in Pb collisions at 5.02 TeV with a multi-phase transport model

    Chao Zhang🇨🇳 · Liang Zheng🇨🇳 · ShuSu Shi🇨🇳 · Zi-Wei Lin🇺🇸

    We study the production of meson in + and Pb collisions using the improved AMPT model considering both coalescence and independent fragmentation of charm quarks after the Cronin broadening are included. After a detailed discussion of the improvements implemented in the AMPT model for heavy quark production, we show that the modified AMPT model can provide good description of meson spectra in Pb collisions, the data at different centrality and data in both mid- and forward (backward) rapidities. We also studied the effects of nuclear shadowing and parton cascade on the rapidity dependence of meson production and . Our results indicate that having the same strength of the Cronin (i.e value) obtained from the mid-rapidity data leads to a considerable overestimation of the meson spectra and data at high in the backward rapidity. As a result, the is determined via a fitting of the data across various rapidities. This work lays the foundation for a better understanding of cold-nuclear-matter (CNM) effects in relativistic heavy-ion collisions.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.06099 [pdf]
    EPJC(2024)·5 citations
  6. 06

    [Submitted on 11 Mar 2024]

    Neutrinoless double- decay and double Gamow-Teller transitions

    Y. K. Wang🇨🇳 · P. W. Zhao🇨🇳 · J. Meng🇨🇳

    The neutrinoless double- () decay and the double Gamow-Teller (DGT) transition are investigated with the state-of-the-art Relativistic Configuration-interaction Density functional theory. A strong linear correlation between the nuclear matrix elements (NMEs) of the decay and the DGT transition is demonstrated. This linear correlation is found to originate from the similarity of the leading-order term of the -decay operator and the DGT-transition one, as revealed by expanding the -decay operator in terms of the spherical harmonics. The present results provide a strong support to constrain the -decay NMEs through the double charge-exchange reactions.

    Comments:
    13 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2403.06455 [pdf]
    PLB(2024)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE