Wed·Aug 21, 2024Wednesday·August 21, 2024

1. 01*

   Optimised neutron yield calculations from ($\alpha ,n$) reactions with the modified SOURCES4 code

   Mihaela Parvu🇷🇴 · Piotr Krawczun · Vitaly A. Kudryavtsev🇬🇧

   The sensitivity of underground experiments searching for rare events such as dark matter, neutrino interactions or several beyond the standard model phenomena is often limited by the background caused by neutrons from spontaneous fission and ($\alpha ,n$) reactions. A number of codes exist to calculate neutron yields and energy spectra due to these processes. In this paper we present new calculations of neutron production using the modified SOURCES4A code with recently updated cross-sections for ($\alpha ,n$) reactions and the comparison of the results with available experimental data. The cross-sections for ($\alpha ,n$) reactions in SOURCES4 have been taken from reliable experimental data where possible, complemented by the calculations with EMPIRE 2.19/3.2.3, TALYS 1.96 or evaluated data library JENDL-5 where the data were scarce or unavailable.

   nucl-exhep-exAppl.Radiat.Isot.(2025)·3 citations
2. 02*

   Search for magnetic monopole pair production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{{}_{\text{NN}}}}=5.36$ TeV with the ATLAS detector at the LHC

   ATLAS Collaboration

   This Letter presents a search for highly ionizing magnetic monopoles in 262$\mu$b${}^{-1}$ of ultraperipheral Pb+Pb collision data at $\sqrt{s_{{}_{\text{NN}}}}=5.36$ TeV collected by the ATLAS detector at the LHC. A new methodology that exploits the properties of clusters of hits reconstructed in the innermost silicon detector layers is introduced to study highly ionizing particles in heavy-ion data. No significant excess above the background, which is estimated using a data-driven technique, is observed. Using a nonperturbative semiclassical model, upper limits at 95% confidence level are set on the cross-section for pair production of monopoles with a single Dirac magnetic charge in the mass range of 20-150 GeV. The search significantly improves on the previous cross-section limits for production of low-mass monopoles in ultraperipheral Pb+Pb collisions.

   ↳ hep-exnucl-exPRL(2025)·30 citations
3. 03*

   Lambda transverse polarization in NA61\SHINE at the CERN SPS: feasibility studies

   Yehor Bondar🇵🇱 · Wojciech Florkowski🇵🇱

   The spin polarization of $\Lambda$ hyperons produced in inclusive reactions with unpolarized protons on unpolarized targets has been studied for almost 40 years. The NA61\SHINE experiment at the CERN SPS has a great potential to study transverse polarization in p-p and p-A collisions. In this work, we discuss the impact of magnetic field and limited detector acceptance on the possible polarization measurement by this experiment. Our analysis shows that the magnetic field impact on the $\Lambda$ polarization due to precession is one order of magnitude smaller than the detector acceptance-based polarization bias, and the identification of an experimental signal similar to that observed before by other experiments is possible.

   ↳ hep-phnucl-exnucl-thActa Phys.Polon.B(2024)·1 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.