Mass measurements of neutron-rich nuclides using the Canadian Penning Trap to inform predictions in the $r$-process rare-earth peak region probe the $r$-process rare-earth peak

• DOI: 10.48550/arxiv.2411.06310
• Publication Date: 2024-11-09
• Authors: D. Ray; Nicole Vassh; B. Liu; A. A. Valverde; M. Brodeur; J. A. Clark; G. C. McLaughlin; Matthew Mumpower; R. Orford; W. S. Porter; G. Savard; K. S. Sharma; Rebecca Surman; F. Buchinger; D. P. Burdette; Nathan Callahan; A. T. Gallant; D. E. M. Hoff; K. Kolos; F. G. Kondev; G. Morgan; F. Rivero; D. Santiago-Gonzalez; N. D. Scielzo; L. Varriano; Christina Weber; G.E. Wilson; Xin Yan
• Keywords: Nuclide; r-process; Penning trap; Trap (plumbing)

Studies aiming to determine the astrophysical origins of nuclei produced by rapid neutron capture process ($r$ process) rely on nuclear properties as inputs for simulations. The solar abundances can be used a benchmark such calculations, with $r$-process rare-earth peak (REP) around mass number ($A$) $164$ being special interest due its presently unknown origin. With advancement rare isotope beam production over last decade and improvement in experimental sensitivities, many these REP nuclides have become accessible measurement. Masses are one most critical they impact multiple properties, namely neutron-separation energies, rates, $\beta$-decay $\beta$-delayed emission probabilities. In this work, we report masses 20 neutron-rich (along Ba, La, Ce, Pr, Nd, Pm, Gd, Dy Ho isotopic chains) at CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility Argonne National Laboratory. were measured Canadian Penning trap (CPT) spectrometer using Phase-Imaging Ion-Cyclotron-Resonance (PI-ICR) technique. We then use new along previously published CPT inform predictions Markov Chain Monte Carlo (MCMC) procedure identify conditions consistent both data measurements. show that MCMC responds updated information, producing refined results abundances.