Fri·Aug 25, 2023Friday·August 25, 2023

1. 01*

   Development of fast-response PPAC with strip-readout for heavy-ion beams

   Shutaro Hanai🇯🇵 · Shinsuke Ota🇯🇵 · Reiko Kojima · Shoichiro Masuoka🇯🇵 · Masanori Dozono🇯🇵 · Nobuaki Imai🇯🇵 · Shin'ichiro Michimasa🇯🇵 · Susumu Shimoura · Juzo Zenihiro🇯🇵 · Kento Inaba · Yuto Hijikata🇯🇵 · Ru Longhi · Ryo Nakajima

   A strip-readout parallel-plate avalanche counter (SR-PPAC) has been developed aiming at the high detection efficiency and good position resolution in high-intensity heavy-ion measurements. The performance was evaluated using 115 MeV/u ${}^{132}$Xe, 300 MeV/u ${}^{132}$Sn, and 300 MeV/u ${}^{48}$Ca beams. A detection efficiency beyond 99% for these beams is achieved even at an incident beam intensity of 0.7 billion particles per second. The best position resolution achieved is 235 um (FWHM).

   nucl-exphysics.ins-detPTEP(2023)·1 citation
2. 02*

   Neutron Scattering off One-Neutron Halo Nuclei in Halo Effective Field Theory

   Xu Zhang🇨🇳 · Hai-Long Fu🇨🇳 · Feng-Kun Guo🇨🇳 · Hans-Werner Hammer🇩🇪

   Neutron scattering off neutron halos can provide important information about the internal structure of nuclei close to the neutron drip line. In this work, we use halo effective field theory to study the $s$-wave scattering of a neutron and the spin-parity $J^P={\frac{1}{2}}^{+}$ one-neutron halo nuclei ${}^{11}\mathrm{Be}$, ${}^{15}\mathrm{C}$, and ${}^{19}\mathrm{C}$ at leading order. In the $J=1$ channel, the only inputs to the Faddeev equations are their one-neutron separation energies. In the $J=0$ channel, the neutron-neutron scattering length and the two-neutron separation energies of ${}^{12}\mathrm{Be}$, ${}^{16}\mathrm{C}$ and ${}^{20}\mathrm{C}$ enter as well. The numerical results show that the total $s$-wave cross sections in the $J=1$ channel at threshold are of the order of a few barns. In the $J=0$ channel, these cross sections are of the order of a few barns for $n$-${}^{11}\mathrm{Be}$ and $n$-${}^{19}\mathrm{C}$ scattering, and about 60 $\mathrm{mb}$ for the $n$-${}^{15}\mathrm{C}$ scattering. The appearance of a pole in $p\cot \delta$ close to zero in all three cases indicates the existence of a virtual Efimov state close to threshold in each of the ${}^{12}\mathrm{Be}$, ${}^{16}\mathrm{C}$, and ${}^{20}\mathrm{C}$ systems. Observation of this pole would confirm the presence of Efimov physics in halo nuclei. The dependence of the results on the neutron-core scattering length is also studied.

   ↳ nucl-thhep-phnucl-exPRC(2023)·8 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.