Tue·Jul 5, 2022Tuesday·July 5, 2022

1. 01*

   Measurement of ${}_{\mathrm{\Lambda }}^4\mathrm{H}$ and ${}_{\mathrm{\Lambda }}^4\mathrm{He}$ binding energy in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV

   STAR Collaboration: M. S. Abdallah🇪🇬 · B. E. Aboona🇺🇸 · J. Adam🇺🇸 · L. Adamczyk🇵🇱 · J. R. Adams🇺🇸 · J. K. Adkins🇺🇸 · I. Aggarwal🇮🇳 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · D. M. Anderson🇺🇸 · E. C. Aschenauer🇺🇸 · M. U. Ashraf🇨🇳 and 360 other authors

   Measurements of mass and $\Lambda$ binding energy of ${}_{\mathrm{\Lambda }}^4\mathrm{H}$ and ${}_{\mathrm{\Lambda }}^4\mathrm{He}$ in Au+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}=3$ GeV are presented, with an aim to address the charge symmetry breaking (CSB) problem in hypernuclei systems with atomic number A = 4. The $\Lambda$ binding energies are measured to be $2.22\pm 0.06(stat.)\pm 0.14(syst.)$ MeV and $2.38\pm 0.13(stat.)\pm 0.12(syst.)$ MeV for ${}_{\mathrm{\Lambda }}^4\mathrm{H}$ and ${}_{\mathrm{\Lambda }}^4\mathrm{He}$, respectively. The measured $\Lambda$ binding-energy difference is $0.16\pm 0.14(stat.)\pm 0.10(syst.)$ MeV for ground states. Combined with the $\gamma$-ray transition energies, the binding-energy difference for excited states is $-0.16\pm 0.14(stat.)\pm 0.10(syst.)$ MeV, which is negative and comparable to the value of the ground states within uncertainties. These new measurements on the $\Lambda$ binding-energy difference in A = 4 hypernuclei systems are consistent with the theoretical calculations that result in $\mathrm{\Delta }{\mathrm{B}}_{\mathrm{\Lambda }}^4(1_{\mathrm{exc}}^{+})\approx -\mathrm{\Delta }{\mathrm{B}}_{\mathrm{\Lambda }}^4(0_{g.s.}^{+})<0$ and present a new method for the study of CSB effect using relativistic heavy-ion collisions.

   nucl-exPLB(2022)·23 citations
2. 02*

   Single Particle Configurations of the Excited States of ${}^{203}$Po

   S. Chatterjee · A. Ghosh · D. Arora · S. Das🇺🇸 · B. Mondal · S. Samanta🇮🇳 · R. Raut🇮🇳 · S. S. Ghugre🇮🇳 · P. C. Srivastava🇮🇳 · A. K. Sinha · U. Garg🇺🇸 · H. K. Singh and 8 other authors

   Excited states of the ${}^{203}$Po ($Z=84,N=119$) have been investigated after populating them through ${}^{194}$Pt(${}^{13}$C,4n) fusion-evaporation reaction at E${}_{beam}$ = 74 MeV and using a large array of Compton suppressed HPGe clover detectors as the detection setup for the emitted $\gamma$-rays. Standard techniques of $\gamma$-ray spectroscopy have been applied towards establishing the level structure of the nucleus. Twenty new $\gamma$-ray transitions have been identified therein, through $\gamma -\gamma$ coincidence measurements, and spin-parity assignments of several states have been determined or confirmed, following the angular correlation and linear polarization measurements on the observed $\gamma$-rays. The excited states have been interpreted in the framework of large basis shell model calculations, while comparing their calculated and experimental energies. They have been principally ascribed to proton population in the $h_{9/2}$ and $i_{13/2}$ orbitals outside the $Z=82$ closure and neutron occupation of the $f_{5/2}$, $p_{3/2}$ and $i_{13/2}$ orbitals in the $N=126$ shell.

   nucl-exPRC(2022)·5 citations
3. 03*

   Nuclear Level Density and $\gamma$-ray Strength Function of ${}^{63}\mathrm{Ni}$

   Vetle W. Ingeberg🇳🇴 · Pete Jones🇿🇦 · Lumkile Msebi🇿🇦 · Sunniva Siem🇳🇴 · Mathis Wiedeking · Abraham Aungwa · Maluba V. Chisapi · Elena Lawrie🇿🇦 · Kgashane Malatji🇿🇦 · Lucky Makhathini🇿🇦 · Sive Noncolela🇿🇦 · Obed Shirinda🇿🇦

   The nuclear level density (NLD) and $\gamma$-ray strength function ($\gamma$SF) of ${}^{63}\mathrm{Ni}$ have been investigated using the Oslo method. The extracted NLD is compared with previous measurements using particle evaporation and those found from neutron resonance spacing. The $\gamma$SF was found to feature a strong low energy enhancement that could be explained as M1 strength based on large scale shell model calculations. Comparison of $\gamma$SFs measured with the Oslo method for various $\mathrm{Ni}$ isotopes reveals systematic changes to the strength below $5$ MeV with increasing mass.

   nucl-exPRC(2022)·10 citations
4. 04*

   Neutron skin of 48Ca deduced from interaction cross section

   Masayuki Matsuzaki · Masanobu Yahiro🇯🇵

   The neutron skin thickness of 48Ca was deduced from the interaction cross section by adopting a microscopic optical potential. The optical potential used was constructed by folding a chiral g matrix and the Skyrme mean-field densities renormalized by considering the information of the interaction cross section. The result was R_skin = 0.139 \pm 0.058 fm.

   ↳ nucl-thnucl-exMod.Phys.Lett.A(2022)·3 citations
5. 05*

   Search for MeV Electron Recoils from Dark Matter in EXO-200

   EXO-200 Collaboration: S. Al Kharusi · G. Anton · I. Badhrees · P.S. Barbeau · D. Beck · V. Belov · T. Bhatta · M. Breidenbach · T. Brunner · G.F. Cao · W.R. Cen · C. Chambers and 94 other authors

   We present a search for electron-recoil signatures from the charged-current absorption of fermionic dark matter using the EXO-200 detector. We report an average electron recoil background rate of $6.8\times 10^{-4}\mathrm{cts}{\mathrm{kg}}^{-1}{\mathrm{yr}}^{-1}{\mathrm{keV}}^{-1}$ above $4\mathrm{MeV}$ and find no statistically significant excess over our background projection. Using a total ${}^{136}\mathrm{Xe}$ exposure of $234.1\mathrm{kg}\mathrm{yr}$ we exclude new parameter space for the charged-current absorption cross-section for dark matter masses between $m_{\chi }=2.6\mathrm{MeV}-11.6\mathrm{MeV}$ with a minimum of $6\times 10^{-51}{\mathrm{cm}}^2$ at $8.3\mathrm{MeV}$ at the $90\%$ confidence level.

   ↳ hep-exnucl-exPRD(2023)·16 citations
6. 06*

   Towards Precise and Accurate Calculations of Neutrinoless Double-Beta Decay: Project Scoping Workshop Report

   V. Cirigliano🇺🇸 · Z. Davoudi🇺🇸 · J. Engel🇺🇸 · R.J. Furnstahl🇺🇸 · G. Hagen🇺🇸 · U. Heinz🇺🇸 · H. Hergert🇺🇸 · M. Horoi🇺🇸 · C.W. Johnson🇺🇸 · A. Lovato🇺🇸 · E. Mereghetti🇺🇸 · W. Nazarewicz🇺🇸 and 11 other authors

   We present the results of a National Science Foundation (NSF) Project Scoping Workshop, the purpose of which was to assess the current status of calculations for the nuclear matrix elements governing neutrinoless double-beta decay and determine if more work on them is required. After reviewing important recent progress in the application of effective field theory, lattice quantum chromodynamics, and ab initio nuclear-structure theory to double-beta decay, we discuss the state of the art in nuclear-physics uncertainty quantification and then construct a road map for work in all these areas to fully complement the increasingly sensitive experiments in operation and under development. The road map contains specific projects in theoretical and computational physics as well as an uncertainty-quantification plan that employs Bayesian Model Mixing and an analysis of correlations between double-beta-decay rates and other observables. The goal of this program is a set of accurate and precise matrix elements, in all nuclei of interest to experimentalists, delivered together with carefully assessed uncertainties. Such calculations will allow crisp conclusions from the observation or non-observation of neutrinoless double-beta decay, no matter what new physics is at play.

   ↳ nucl-thhep-phnucl-exJ.Phys.G(2022)·51 citations
7. 07*

   Multipole decomposition of tensor interactions of fermionic probes with composite particles and BSM signatures in nuclear reactions

   Ayala Glick-Magid🇮🇱 · Doron Gazit🇮🇱

   A multipole decomposition of a cross-section is a useful tool to simplify the analysis of reactions due to their symmetry properties. By using a new approach to decompose antisymmetric tensor-type interactions within the multipole analysis, we introduce a general mathematical formalism for working with tensor couplings. This allows us to present a general tensor nuclear response, which is particularly useful for ongoing beta-decay experiments looking for physics beyond the Standard Model, as well as other exotic particle scatterings off nuclei, e.g., in dark matter direct detection experiments. Using this method, beyond the Standard Model operators identify with the known Standard Model operators, eliminating the need for calculations of additional matrix elements. We present in detail BSM expressions useful for beta-decay experiments and give an exemplary application for 6He beta-decay, although the formalism is easily generalizable for calculating other exotic scattering reactions.

   ↳ nucl-thhep-phnucl-exPRD(2023)·13 citations
8. 08*

   Theoretical study of the d(d,p)3H and d(d,n)3He processes at low energies

   M. Viviani (INFN-PI)🇮🇹 · L. Girlanda (UniSalento & INFN-LE)🇮🇹 · A. Kievsky (INFN-PI)🇮🇹 · D. Logoteta (UniPI)🇮🇹 · L.E. Marcucci (UniPI & INFN-PI)🇮🇹

   We present a theoretical study of the processes d(d,p)3H and d(d,n)3He at energies of interest for energy production and for big-bang nucleosynthesis. We accurately solve the four body scattering problem using the ab-initio hyperspherical harmonic method, starting from nuclear Hamiltonians which include modern two- and three-nucleon interactions, derived in chiral effective field theory. We report results for the astrophysical factor, the quintet suppression factor, and various single and double polarized observables. An estimate of the "theoretical uncertainty" for all these quantities is provided by varying the cutoff parameter used to regularize the chiral interactions at high momentum.

   ↳ nucl-thnucl-exPRL(2023)·5 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.