Wed·Nov 2, 2022Wednesday·November 2, 2022

1. 01*

   Study of the ${}^{22}$Mg waiting point relevant for x-ray burst nucleosynthesis via the ${}^{22}$Mg($\alpha$,$p$)${}^{25}$Al reaction

   H. Jayatissa🇺🇸 · M. L. Avila🇺🇸 · K. E. Rehm🇺🇸 · P. Mohr🇭🇺 · Z. Meisel🇺🇸 · J. Chen🇨🇳 · C. R. Hoffman🇺🇸 · J. Liang🇨🇳 · C. Müller-Gatermann🇩🇪 · D. Neto🇺🇸 · W. J. Ong🇺🇸 · A. Psaltis🇨🇦 and 4 other authors

   The ${}^{22}$Mg($\alpha$,$p$)${}^{25}$Al reaction rate has been identified as a major source of uncertainty for understanding the nucleosynthesis flow in Type-I x-ray bursts (XRBs). We report a direct measurement of the energy- and angle-integrated cross sections of this reaction in a 3.3-6.9 MeV center-of-mass energy range using the MUlti-Sampling Ionization Chamber (MUSIC). The new ${}^{22}$Mg($\alpha$,$p$)${}^{25}$Al reaction rate is a factor of $\sim$4 higher than the previous direct measurement of this reaction within temperatures relevant for XRBs, resulting in the ${}^{22}$Mg waiting point of x-ray burst nucleosynthesis flow to be significantly bypassed via the ($\alpha ,p$) reaction

   nucl-exPRL(2023)·13 citations
2. 02*

   Measurements of $K_{\text{S}}^0$, $\Lambda$ and $\bar{\Lambda }$ production in 120 GeV/$c$ p + C interactions

   NA61/SHINE Collaboration: H. Adhikary · K.K. Allison · N. Amin · E.V. Andronov · T. Antićić · I.-C. Arsene · Y. Balkova · M. Baszczyk · D. Battaglia · S. Bhosale · A. Blondel · M. Bogomilov and 145 other authors

   This paper presents multiplicity measurements of $K_{\text{S}}^0$, $\Lambda$, and $\bar{\Lambda }$ produced in 120 GeV/$c$ proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different periods. Decays of these neutral hadrons impact the measured ${\pi }^{+}$, ${\pi }^{-}$, $p$ and $\bar{p}$ multiplicities in the 120 GeV/$c$ proton-carbon reaction, which are crucial inputs for long-baseline neutrino experiment predictions of neutrino beam flux. The double-differential multiplicities presented here will be used to more precisely measure charged-hadron multiplicities in this reaction, and to re-weight neutral hadron production in neutrino beam Monte Carlo simulations.

   ↳ hep-exnucl-exPRD(2023)·12 citations
3. 03*

   Microscopic formulation of the interacting boson model for reflection asymmetric nuclei

   Kosuke Nomura🇭🇷

   Reflection asymmetric, octupole shapes in nuclei are a prominent aspect of nuclear structure, and have been recurrently studied over the decades. Recent experiments using radioactive-ion beams have provided evidence for stable octupole shapes. A variety of nuclear models have been employed for the related theoretical analyses. We review recent studies on the nuclear octupole shapes and collective excitations within the interacting boson model. A special focus is placed on the microscopic formulation of this model by using the mean-field method that is based on the framework of nuclear density functional theory. As an illustrative example, a stable octupole deformation, and a shape phase transition as a function of nucleon number that involves both quadrupole and octupole degrees of freedom are shown to occur in light actinides. Systematic spectroscopic studies indicate enhancement of the octupole collectivity in a wide mass region. Couplings between the octupole and additional degrees of freedom are incorporated in a microscopic manner in the boson system, and shown to play a crucial role in the description of the related intriguing nuclear structure phenomena such as the shape coexistence.

   ↳ nucl-thnucl-exIJMPE(2023)·6 citations
4. 04*

   Ab initio no-core shell model description of ${}^{10-14}$C isotopes

   Priyanka Choudhary🇮🇳 · Praveen C. Srivastava🇮🇳 · Michael Gennari🇨🇦 · Petr Navratil🇨🇦

   We present a systematic study of the ${}^{10-14}\text{C}$ isotopes within the \textit{ab initio} no-core shell model theory. We apply four different realistic nucleon-nucleon (NN) interactions: (i) the charge-dependent Bonn 2000 (CDB2K) potential (ii) the inside non-local outside Yukawa (INOY) potential (iii) the next-to-next-to-next-to-leading order (N${}^3$LO) potential, and (iv) the optimized next-to-next-to-leading order (N${}^2$LO${}_{opt}$) potential. We report the low-lying energy spectra of both positive and negative parity states for the ${}^{10-14}\text{C}$ isotopes and investigate the level structures. We also calculate electromagnetic properties such as transition strengths, quadrupole and magnetic moments. The dependence of point-proton radii on the harmonic oscillator frequency and basis space is shown. We present calculations of the translation invariant one-body density matrix in the no-core shell model and discuss isotopic trends in the density distribution. The maximum basis space reached is $10\hslash \Omega$ for ${}^{10}\text{C}$ and $8\hslash \Omega$ for ${}^{11-14}\text{C}$, with a maximum M-scheme dimension of $1.3\times 10^9$ for ${}^{10}\text{C}$. We found that while the INOY interaction gives the best description of the ground state energies, the N${}^3$LO interaction best reproduces the point-proton radii.

   ↳ nucl-thnucl-exPRC(2023)·19 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.