Tue·Aug 27, 2024Tuesday·August 27, 2024

1. 01*

   High-precision mass measurements of the ground and isomeric states in ${}^{124,125}$Ag

   J. Ruotsalainen🇫🇮 · D. A. Nesterenko🇫🇮 · M. Stryjczyk🇫🇮 · A. Kankainen🇫🇮 · L. Al Ayoubi🇫🇮 · O. Beliuskina🇫🇮 · L. Canete🇫🇮 · P. Chauveau🇫🇷 · R. P. de Groote🇫🇮 · P. Delahaye🇫🇷 · T. Eronen🇫🇮 · M. Flayol🇫🇷 and 17 other authors

   The masses of the ground and isomeric states in ${}^{124,125}$Ag have been measured using the phase-imaging ion-cyclotron-resonance technique at the JYFLTRAP double Penning trap mass spectrometer. The ground states of ${}^{124}$Ag and ${}^{125}$Ag were found to be 30(250) keV and 250(430) keV less bound but 36 and 110 times more precise than in the Atomic Mass Evaluation 2020, respectively. The excitation energy of ${}^{124}$Ag${}^m$, $E_x=188.2(25)$ keV, was determined for the first time. The new precise mass values have been utilised to study the evolution of nuclear structure via two-neutron separation energies. The impact on the astrophysical rapid neutron capture process has been investigated via neutron-capture reaction rate calculations. The precision measurements indicate a more linear trend in two-neutron separation energies and reduce the mass-related uncertainties for the neutron-capture rate of ${}^{124}$Ag$(n,\gamma {)}^{125}$Ag by a factor of around 100. The new mass values also improve the mass of ${}^{123}$Pd, previously measured using ${}^{124}$Ag as a reference.

   nucl-exPRC(2025)·2 citations
2. 02*

   The MUSE Beamline Calorimeter

   W. Lin🇺🇸 · T. Rostomyan🇨🇭 · R. Gilman🇺🇸 · S. Strauch🇺🇸 · C. Meier🇨🇭 · C. Nestler🇨🇭 · M. Ali🇺🇸 · H. Atac🇺🇸 · J. C. Bernauer🇺🇸 · W. J. Briscoe🇺🇸 · A. Christopher Ndukwe🇺🇸 · E. W. Cline🇺🇸 and 31 other authors

   The MUon Scattering Experiment (MUSE) was motivated by the proton radius puzzle arising from the discrepancy between muonic hydrogen spectroscopy and electron-proton measurements. The MUSE physics goals also include testing lepton universality, precisely measuring two-photon exchange contribution, and testing radiative corrections. MUSE addresses these physics goals through simultaneous measurement of high precision cross sections for electron-proton and muon-proton scattering using a mixed-species beam. The experiment will run at both positive and negative beam polarities. Measuring precise cross sections requires understanding both the incident beam energy and the radiative corrections. For this purpose, a lead-glass calorimeter was installed at the end of the beam line in the MUSE detector system. In this article we discuss the detector specifications, calibration and performance. We demonstrate that the detector performance is well reproduced by simulation, and meets experimental requirements.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2025)·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.