Thu·May 25, 2023Thursday·May 25, 2023

1. 01*

   ${\beta }^{-}$ decay of neutron-rich ${}^{45}$Cl at magic number N=28

   Soumik Bhattacharya · Vandana Tripathi · S. L. Tabor · A. Volya · P. C. Bender · C. Benetti · M. P. Carpenter · J. J. Carroll · A. Chester · C. J. Chiara · K. Childers · B. R. Clark and 16 other authors

   Results from the study of ${\beta }^{-}$-decay of ${}^{45}$Cl, produced in the fragmentation of a 140-MeV/u ${}^{48}$Ca beam, are presented. The half-life for ${}^{45}$Cl $\beta$-decay is measured to be 513(36) ms. The ${\beta }^{-}$ and ${\beta }^{-}1n$ decay of ${}^{45}$Cl populated excited states in ${}^{45,44}$Ar, respectively. On the basis of $\gamma$-ray singles and $\gamma$-$\gamma$ coincidence data, decay schemes for the two daughter nuclei have been established. They are compared with shell model calculations using the FSU interaction. The low-lying negative parity states for ${}^{45}$Ar are well described by a single particle (neutron) occupying orbitals near the Fermi surface, whereas neutron excitations across the $N=20$ shell gap are needed to explain the positive-parity states which are expected to be populated in allowed Gamow-Teller $\beta$-decay of ${}^{45}$Cl. The highest $\beta$-feeding to the 5/2${}^{+}$ state in ${}^{45}$Ar from the ground state of ${}^{45}$Cl points towards a 3/2${}^{+}$ spin-parity assignment of the ground state of the parent over the other possibility of 1/2${}^{+}$. The high Q${}_{{\beta }^{-}}$ value of ${}^{45}$Cl decay allows for the population of $1p1h$ states above the neutron separation energy in ${}^{45}$Ar leading to positive parity states of ${}^{44}$Ar being populated by removal of one neutron from the $sd$ shell. The spin-parities of the excited levels in ${}^{44}$Ar are tentatively assigned for the first time by comparison with the shell model calculations. The 2978~keV level of ${}^{44}$Ar is identified as the excited 0${}^{+}$ level which could correspond to a different configuration from the ground state.

   nucl-exPRC(2023)·7 citations
2. 02*

   Cross Section Measurement of the ${}^{82}$Kr(p,$\gamma$)${}^{83}$Rb Reaction in Inverse Kinematics

   A. Tsantiri (1, 2, 3)🇺🇸 · A. Palmisano-Kyle (1, 2, 3) · A. Spyrou (1, 2, 3) · P. Mohr (4)🇺🇸 · H. C. Berg (1, 2, 3)🇺🇸 · P. A. DeYoung (5) · A. C. Dombos (1, 2, 3)🇺🇸 · P. Gastis (6, 3) · E. C. Good (2, 3)🇺🇸 · C. M. Harris (1, 2, 3)🇺🇸 · S. N. Liddick (7, 2, 3)🇺🇸 · S. M. Lyons (1, 2, 3)🇺🇸 and 7 other authors

   The total cross section of the ${}^{82}$Kr(p,$\gamma$)${}^{83}$Rb reaction was measured for the first time at effective center-of-mass energies between 2.4 and 3.0 MeV, within the relevant Gamow window for the astrophysical $\gamma$ process. The experiment took place at the National Superconducting Cyclotron Laboratory at Michigan State University using the ReA facility. A ${}^{82}$Kr beam was directed onto a hydrogen gas cell located at the center of the Summing NaI(Tl) (SuN) detector. The obtained spectra were analyzed using the $\gamma$-summing technique and the extracted cross section was compared to standard statistical model calculations using the \textsc{non-smoker} and \textsc{talys} codes. The comparison indicates that standard statistical model calculations tend to overproduce the cross section of the ${}^{82}$Kr(p,$\gamma$)${}^{83}$Rb reaction relative to the experimentally measured values. Furthermore, the experimental data was used to provide additional constraints on the nuclear level density and $\gamma$-ray strength function used in the statistical model calculations.

   nucl-exPRC(2023)·7 citations
3. 03*

   Ab initio study of nuclear clustering in hot dilute nuclear matter

   Zhengxue Ren🇩🇪 · Serdar Elhatisari🇹🇷 · Timo A. Lähde🇩🇪 · Dean Lee🇺🇸 · Ulf-G. Meißner🇩🇪

   We present a systematic ab initio study of clustering in hot dilute nuclear matter using nuclear lattice effective field theory with an SU(4)-symmetric interaction. We introduce a method called light-cluster distillation to determine the abundances of dimers, trimers, and alpha clusters as a function of density and temperature. Our lattice results are compared with an ideal gas model composed of free nucleons and clusters. Excellent agreement is found at very low density, while deviations from ideal gas abundances appear at increasing density due to cluster-nucleon and cluster-cluster interactions. In addition to determining the composition of hot dilute nuclear matter as a function of density and temperature, the lattice calculations also serve as benchmarks for virial expansion calculations, statistical models, and transport models of fragmentation and clustering in nucleus-nucleus collisions.

   ↳ nucl-thhep-phnucl-exPLB(2024)·37 citations
4. 04*

   Systematic shell-model study for structure and isomeric states in ${}^{200-210}$Po isotopes

   Sakshi Shukla🇮🇳 · Praveen C. Srivastava🇮🇳 · Kosuke Nomura🇯🇵 · Larry Zamick

   We report systematic large-scale shell-model calculation for Po isotopes with $A=$ 200 to 210. We have performed calculations using KHH7B interaction in the model space $Z$ = 58-114 and $N$ = 100-164 around doubly-magic ${}^{208}$Pb. We allow valence neutrons to occupy in the $1f_{5/2}$, $2p_{3/2}$, $2p_{1/2}$, and $0i_{13/2}$ orbitals, while two valence protons beyond $Z=82$ are occupied in $0h_{9/2}$, $1f_{7/2}$ and $0i_{13/2}$ orbitals. The calculated energies and electromagnetic properties are compared with the available experimental data and predicted where experimental data are not available. We have also reported shell-model results for different isomeric states of these nuclei.

   ↳ nucl-thnucl-exNPA(2024)·5 citations
5. 05*

   Extraction of the Parton Momentum-Fraction Dependence of Generalized Parton Distributions from Exclusive Photoproduction

   Jian-Wei Qiu🇺🇸 · Zhite Yu🇺🇸

   The $x$ dependence of hadrons' generalized parton distributions (GPDs) $\mathcal{F}(x,\xi ,t)$ is the most difficult to extract from the existing known processes, while the $\xi$ and $t$ dependence are uniquely determined by the kinematics of the scattered hadron. We study the single diffractive hard exclusive processes for extracting GPDs in the photoproduction. We demonstrate quantitatively the enhanced sensitivity on extracting the $x$ dependence of various GPDs from the photoproduction cross sections, as well as the asymmetries constructed from photon polarization and hadron spin that could be measured at JLab Hall D by GlueX Collaboration and future facilities.

   ↳ hep-phhep-exhep-latnucl-ex+1PRL(2023)·42 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.