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Nuclear Theory·nucl-th

Tuesday·June 25, 2024

10 papers—6 primary·4 cross-listed

All10Primary6Cross-lists4
  1. 07

    [Submitted on 30 May 2024] (cross-list from nucl-ex)

    Am isomer yield in Am reaction

    V.M. Maslov

    The reaction 243 Am (n, 2n) populates the T of 16 hours ground state 242 g Am with J of 1 or the 242 m Am isomer state J of 5 with T of 141 years. The former state 242 g Am mostly beta decays to 242 Cm, or transmutes to 242 Pu via electron capture. The absolute yield of 242 g Am is compatible with the measured data, estimated by the alpha activity of 242 Cm by Norris in 1983. The branching ratio defined by the ratio of the populations of the lowest intrinsic states of 242 Am. Calculated yields of ground 242 g Am and isomer 242 m Am states of the residual nucleus 242 Am are used to predict the relative yield of isomer. These populations defined by the gamma decay of the excited states, described by the standard kinetic equation. The ordering of the low and high spin states is different in case of 236 Np and 242 Am nuclei, that explains different shapes of relative yields near the (n, 2n) reaction threshold, though the excitation energy dependences are similar. Data of 243 Am (n, F) at 5 MeV and 15 MeV by Drapchinsky in 2004, support calculated 243Am (n,xnf) prefission neutron contribution to prompt fission neutron spectra and calculated exclusive neutron spectra of 243 Am (n, 2n) feeding the 242 g Am and isomer 242 m Am states.

    Comments:
    arXiv admin note: substantial text overlap with arXiv:2405.18366
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2406.15445 [pdf]
    0 citations
  2. 08

    [Submitted on 23 Jun 2024] (cross-list from nucl-ex)

    Measurement of the cross sections at

    M. Mihovilovič🇸🇮 · L. Doria🇩🇪 · P. Achenbach🇺🇸 · A. M. Ankowski🇵🇱 · S. Bacca🇩🇪 · D. Bosnar🇭🇷 · A. Denig🇩🇪 · M. O. Distler🇩🇪 · A. Esser🇩🇪 · I. Friščić🇭🇷 · C. Giusti🇮🇹 · M. Hoek🇩🇪 and 13 other authors

    We present the findings of a study based on a new inelastic electron-scattering experiment on the nucleus focusing on the kinematic region of . The measured cross section is sensitive to the transverse response function and provides a stringent test of theoretical models, as well as of the theoretical assumptions made in Monte-Carlo event-generator codes developed for the interpretation of neutrino-nucleus experiments, such as DUNE and HyperK. We find that modern generators such as GENIE and GiBUU reproduce our new experimental data within 10.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2406.16059 [pdf]
    Few Body Syst.(2024)·11 citations
  3. 09

    [Submitted on 23 Jun 2024] (cross-list from quant-ph)

    Quantum computer specification for nuclear structure calculations

    Ching-Hwa Wee🇲🇾 · Meng-Hock Koh🇲🇾 · Yung Szen Yap🇲🇾

    Recent studies to solve nuclear structure problems using quantum computers rely on a quantum algorithm known as Variational Quantum Eigensolver (VQE). In this study, we calculate the correlation energy in Helium-6 using VQE, with a \textit{full-term} unitary-paired-coupled-cluster-doubles (UpCCD) ansatz on a quantum computer simulator and implement a set of custom termination criteria to shorten the optimization time. Using this setup, we test out noisy quantum computer simulators of various coherence times and quantum errors to find the required specification for such calculations. We also look into the contribution of errors from the quantum computers and optimization process. We find that the minimal specification of 5~ms coherence times and quantum errors is required to reliably reproduce state-vector results within 8\% discrepancy. Our study indicates the possibility of performing VQE calculations using a full-term UpCCD ansatz on a slightly noisy quantum computer, without implementing quantum error correction.

    Comments:
    9 pages, 4 figures, 1 table
    Subjects:
    Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
    arXiv:
    2406.16165 [pdf]
    2 citations
  4. 10

    [Submitted on 24 Jun 2024] (cross-list from hep-lat)

    Scale setting and hadronic properties in light quark sector with -flavor Wilson fermions at the physical point

    Tatsumi Aoyama (Tokyo U., ISSP)🇯🇵 · Takahiro M. Doi (Kyoto U. and Wako, RIKEN)🇯🇵 · Takumi Doi (Wako, RIKEN)🇯🇵 · Etsuko Itou (Kyoto U., Yukawa Inst., Kyoto and Wako, RIKEN)🇯🇵 · Yan Lyu (Wako, RIKEN)🇯🇵 · Kotaro Murakami (Tokyo Inst. Tech. and Wako, RIKEN)🇯🇵 · Takuya Sugiura (Rissho U. and Wako, RIKEN) (HAL QCD Collaboration)🇯🇵

    We report scale setting and hadronic properties for our new lattice QCD gauge configuration set (HAL-conf-2023). We employ -flavor nonperturbatively improved Wilson fermions with stout smearing and the Iwasaki gauge action on a lattice, and generate configurations of 8,000 trajectories at the physical point. We show the basic properties of the configurations such as the plaquette value, topological charge distribution and their auto-correlation times. The scale setting is performed by detailed analyses of the baryon mass. We calculate the physical results of quark masses, decay constants of pseudoscalar mesons and single hadron spectra in light quark sector. The masses of the stable hadrons are found to agree with the experimental values within a sub-percent level.

    Comments:
    32 pages and 18 figures; v2: reference(s) added; v3: accepted for publication in Phys. Rev. D; v4: typo(s) corrected, published version
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2406.16665 [pdf]
    PRD(2024)·25 citations

Affiliations

first authorsco-authorsvia INSPIRE