Fri·Nov 18, 2022Friday·November 18, 2022

1. 01*

   Neutron polarisation transfer, $C_{x^{\prime }}^n$, in ${\pi }^{+}$ photoproduction off the proton

   M. Bashkanov🇬🇧 · D. P. Watts🇬🇧 · S. J. D. Kay🇨🇦 · S. Abt🇨🇭 · P. Achenbach🇩🇪 · P. Adlarson🇩🇪 · F. Afzal🇩🇪 · Z. Ahmed🇨🇦 · C. S. Akondi🇺🇸 · J. R. M. Annand🇬🇧 · R. Beck🇩🇪 · M. Biroth🇩🇪 and 54 other authors

   We report a first measurement of the double-polarisation observable, $C_{x^{\prime }}$, in ${\pi }^{+}$ photoproduction off the proton. The $C_{x^{\prime }}$ double-polarisation observable represents the transfer of polarisation from a circularly polarised photon beam to the recoiling neutron. The MAMI circularly polarised photon beam impinged on a liquid deuterium target cell, with reaction products detected in the Crystal Ball calorimeter. Ancillary apparatus surrounding the target provided tracking, particle identification and determination of recoil nucleon polarisation. The $C_{x^{\prime }}$ observable is determined for photon energies 800-1400 MeV, providing new constraints on models aiming to elucidate the spectrum and properties of nucleon resonances. This is the first determination of any polarisation observable from the beam-recoil group of observables for this reaction, providing a valuable constraint and systematic check of the current solutions of partial wave analysis based theoretical models.

   nucl-ex1 citation
2. 02*

   The interplay of single-particle and collective motions in the low-lying states of ${}_{\Lambda }^{21}$Ne with quadrupole-octupole correlations

   H. J. Xia🇨🇳 · X. Y. Wu🇨🇳 · H. Mei🇷🇺 · J. M. Yao🇨🇳

   The beyond mean-field approach for low-lying hypernuclear states is extended by mixing the configurations associated with both single-particle and quadrupole-octupole collective excitations within the generator coordinate method based on a covariant density functional theory. The method is demonstrated in the application to the low-lying states of ${}_{\Lambda }^{21}$Ne, where the configurations with the $\Lambda$ hyperon occupying the first (${\Lambda }_s$) and second (${\Lambda }_p$) lowest-energy states are considered. The results indicate that the positive-parity states are dominated by the $\alpha {+}^{12}$C+$\alpha +{\Lambda }_s$ structure. In contrast, the low-lying negative-parity states are dominated by a strong admixture of $\alpha {+}^{16}$O+${\Lambda }_s$ structure and $\alpha {+}^{12}$C+$\alpha +{\Lambda }_p$ structure due to the inclusion of octupole correlations. As a result, the low-lying negative-parity states become much lower than what is expected from the previous studies without the mixing, and the electric multipole transition strengths are significantly quenched.

   ↳ nucl-thnucl-exSCPMA(2023)·10 citations
3. 03*

   Isotopic dependence of $(n,\alpha )$ reaction cross sections for Fe and Sn nuclei

   Sema Kucuksucu · Mustafa Yigit · Nils Paar🇭🇷

   The $(n,\alpha )$ reactions play an important role for the energy generation and the synthesis of chemical elements in the stars, as well as for nuclear engineering and medical applications. The aim of this study is to explore the evolution of $(n,\alpha )$ reactions in Fe and Sn isotope chains in order to assess their properties with the increase of neutrons in target nucleus, and compare with other relevant neutron induced reactions. Model calculations of the cross sections are based on the statistical Hauser-Feshbach model in TALYS implementation, using global optical model potential that is additionally adjusted by the $(n,\alpha )$ cross section data for ${}^{54}$Fe and ${}^{118}$Sn. The calculations of $(n,\alpha )$ reactions in Fe and Sn isotopes provide the insight into their isospin dependence and properties over the complete relevant range of neutron energies. The results show the evolution of the cross sections with pronounced maxima at low-mass isotopes, and rather strong decrease for neutron-rich nuclei consistent with the reduction of the reaction $Q$-value and increased contributions from other exit channels from compound nucleus. The analysis of the Maxwellian averaged cross sections at temperatures in stellar environment shows that while the $(n,\alpha )$ reactions contribute for the low-mass isotopes, in neutron induced reactions with nuclei with neutron excess, $\gamma$ and neutron emission dominate.

   ↳ nucl-thastro-ph.SRnucl-exNPA(2024)·1 citation
4. 04*

   Calibration strategy of the PROSPECT-II detector with external and intrinsic sources

   M. Andriamirado🇺🇸 · A. B. Balantekin🇺🇸 · C. D. Bass🇺🇸 · D. E. Bergeron🇺🇸 · E. P. Bernard🇺🇸 · N. S. Bowden🇺🇸 · C. D. Bryan🇺🇸 · R. Carr🇺🇸 · T. Classen🇺🇸 · A. J. Conant🇺🇸 · A. Delgado🇺🇸 · M. V. Diwan🇺🇸 and 49 other authors

   This paper presents an energy calibration scheme for an upgraded reactor antineutrino detector for the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). The PROSPECT collaboration is preparing an upgraded detector, PROSPECT-II (P-II), to advance capabilities for the investigation of fundamental neutrino physics, fission processes and associated reactor neutrino flux, and nuclear security applications. P-II will expand the statistical power of the original PROSPECT (P-I) dataset by at least an order of magnitude. The new design builds upon previous P-I design and focuses on improving the detector robustness and long-term stability to enable multi-year operation at one or more sites. The new design optimizes the fiducial volume by elimination of dead space previously occupied by internal calibration channels, which in turn necessitates the external deployment. In this paper, we describe a calibration strategy for P-II. The expected performance of externally deployed calibration sources is evaluated using P-I data and a well-benchmarked simulation package by varying detector segmentation configurations in the analysis. The proposed external calibration scheme delivers a compatible energy scale model and achieves comparable performance with the inclusion of an additional AmBe neutron source, in comparison to the previous internal arrangement. Most importantly, the estimated uncertainty contribution from the external energy scale calibration model meets the precision requirements of the P-II experiment.

   ↳ physics.ins-dethep-exnucl-exJINST(2023)·5 citations
5. 05*

   SNOWMASS Neutrino Frontier NF10 Topical Group Report: Neutrino Detectors

   Joshua R. Klein🇺🇸 · Ana Machado🇧🇷 · David Schmitz🇺🇸 · Raimund Strauss (Editors)🇩🇪 · Milind Diwan🇺🇸 · Christopher Jackson🇺🇸 · Jose Maneira🇵🇹 · Kostantinos Mavrokoridis🇬🇧 · Nicola McConkey🇬🇧 · Tanaz Mohai🇺🇸 · Gianluca Petrillo🇺🇸 · Joseph Zennamo (Contributors)🇺🇸

   We discuss here future neutrino detectors with physics goals ranging from the eV to the EeV scale. The focus is on future enabling technologies for such detectors, rather than existing detectors or those under construction. The report includes methodologies across the broad spectrum of neutrino physics: liquid noble and other cryogenic detectors, includin LAr and LXe TPCs; photon-based detectors including technologies enabling hybrid Cherenkov/scintillation detectors; low-threshold detectors which use a wide variety of technologies to probe physics like coherent neutrino-nucleus scattering or detection of cosmic background neutrinos; and ultra-high energy detectors including optical and radio detectors, as well as tracking detectors for use at the forward physics facility of the LHC

   ↳ hep-exnucl-exphysics.ins-det13 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.