Fri·Apr 28, 2023Friday·April 28, 2023

1. 01*

   A novel measurement of the neutron magnetic form factor from A=3 mirror nuclei

   S. N. Santiesteban🇺🇸 · S. Li🇺🇸 · D. Abrams🇺🇸 · S. Alsalmi🇺🇸 · D. Androic🇭🇷 · K. Aniol🇺🇸 · J. Arrington🇺🇸 · T. Averett🇺🇸 · C. Ayerbe Gayoso🇺🇸 · J. Bane🇺🇸 · S. Barcus🇺🇸 · J. Barrow🇺🇸 and 94 other authors

   The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ${}^3$H and ${}^3$He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, $0.6<Q^2<2.9$ GeV${}^2$, where existing measurements give inconsistent results. The precision and $Q^2$ range of this data allow for a better understanding of the current world's data, and suggest a path toward further improvement of our overall understanding of the neutron's magnetic form factor.

   nucl-exPRL(2024)·11 citations
2. 02*

   Hexadecapole strength in the rare isotopes ${}^{74,76}$Kr

   M. Spieker · S.E. Agbemava · D. Bazin · S. Biswas P.D. Cottle · P.J. Farris · A. Gade · T. Ginter · S. Giraud · K.W. Kemper · J. Li · W. Nazarewicz · S. Noji and 5 other authors

   In the Ge-Sr mass region, isotopes with neutron number $N\le 40$ are known to feature rapid shape changes with both nucleon number and angular momentum. To gain new insights into their structure, inelastic proton scattering experiments in inverse kinematics were performed on the rare isotopes ${}^{74,76}$Kr. This work focuses on observables related to the $J^{\pi }=4_1^{+}$ states of the Kr isotopes and, in particular, on the hexadecapole degree of freedom. By performing coupled-channels calculations, hexadecapole deformation parameters ${\beta }_4$ were determined for the $J^{\pi }=4_1^{+}$ states of ${}^{74,76}$Kr from inelastic proton scattering cross sections. Two possible coupled-channels solutions were found. A comparison to predictions from nuclear energy density functional theory, employing both non-relativistic and relativistic functionals, clearly favors the large, positive ${\beta }_4$ solutions. These ${\beta }_4$ values are unambiguously linked to the well deformed prolate configuration. Given the ${\beta }_2-{\beta }_4$ trend, established in this work, it appears that ${\beta }_4$ values could provide a sensitive measure of the nuclear shell structure.

   nucl-exnucl-thPLB(2023)·12 citations
3. 03*

   First study of reaction ${\Xi }^{0}n\to {\Xi }^{-}p$ using ${\Xi }^0$-nucleus scattering at an electron-positron collider

   BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · R. Aliberti · A. Amoroso · M. R. An · Q. An · Y. Bai · O. Bakina · I. Balossino · Y. Ban · V. Batozskaya and 605 other authors

   Using $(1.0087\pm 0.0044)\times 10^{10}$ $J/\psi$ events collected with the BESIII detector at the BEPCII storage ring, the process ${\Xi }^{0}n\to {\Xi }^{-}p$ is studied, where the ${\Xi }^0$ baryon is produced in the process $J/\psi \to {\Xi }^0{\bar{\Xi }}^0$ and the neutron is a component of the ${}^9\mathrm{Be}$, ${}^{12}\mathrm{C}$ and ${}^{197}\mathrm{Au}$ nuclei in the beam pipe. A clear signal is observed with a statistical significance of $7.1\sigma$. The cross section of the reaction ${\Xi }^0+{}^9\mathrm{Be}\to {\Xi }^{-}+p+{}^8\mathrm{Be}$ is determined to be $\sigma ({\Xi }^0+{}^9\mathrm{Be}\to {\Xi }^{-}+p+{}^8\mathrm{Be})=(22.1\pm 5.3_{\mathrm{stat}}\pm 4.5_{\mathrm{sys}})$ mb at the ${\Xi }^0$ momentum of $0.818$ GeV/$c$, where the first uncertainty is statistical and the second is systematic. No significant $H$-dibaryon signal is observed in the ${\Xi }^{-}p$ final state. This is the first study of hyperon-nucleon interactions in electron-positron collisions and opens up a new direction for such research.

   ↳ hep-exhep-phnucl-exnucl-thPRL(2023)·42 citations
4. 04*

   A New Momentum-Integrated Muon Tomography Imaging Algorithm

   JungHyun Bae🇺🇸 · Rose Montgomery🇬🇧 · Stylianos Chatzidakis🇺🇸

   For decades, the application of muon tomography to spent nuclear fuel (SNF) cask imaging has been theoretically evaluated and experimentally verified by many research groups around the world, including Los Alamos National Laboratory in the United States, Canadian Nuclear Laboratory in Canada, the National Institute for Nuclear Physics in Italy, and Toshiba in Japan. Although monitoring of SNF using cosmic ray muons has attracted significant attention as a promising nontraditional nondestructive radiographic technique, the wide application of muon tomography is often limited because of the natural low cosmic ray muon flux at sea level: 100 m-2min-1sr-1. Recent studies suggest measuring muon momentum in muon scattering tomography (MST) applications to address this challenge. Some techniques have been discussed; however, an imaging algorithm for momentum-coupled MST had not been developed. This paper presents a new imaging algorithm for MST which integrates muon scattering angle and momentum in a single M-value. To develop a relationship between muon momentum and scattering angle distribution, various material samples (Al, Fe, Pb, and U) were thoroughly investigated using a Monte Carlo particle transport code GEANT4 simulation. Reconstructed images of an SNF cask using the new algorithm are presented herein to demonstrate the benefit of measuring muon momentum in MST. In this analysis a missing fuel assembly (FA) was located in the dry storage cask.

   ↳ physics.ins-detastro-ph.IMnucl-ex1 citation

* 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.