Wed·Jul 8, 2020Wednesday·July 8, 2020

1. 01*

   Detailed spectroscopy of doubly magic ${}^{132}$Sn

   J. Benito🇪🇸 · L.M. Fraile🇪🇸 · A.Korgul🇵🇱 · M. Piersa🇵🇱 · E.Adamska🇵🇱 · A.N. Andreyev🇬🇧 · R. Álvarez-Rodríguez🇪🇸 · A.E. Barzakh🇷🇺 · G. Benzoni🇮🇹 · T. Berry🇬🇧 · M.J.G. Borge🇨🇭 · M. Carmona🇪🇸 and 76 other authors

   The structure of the doubly magic ${}_{50}^{132}$Sn${}_{82}$ has been investigated at the ISOLDE facility at CERN, populated both by the ${\beta }^{-}$decay of ${}^{132}$In and ${\beta }^{-}$-delayed neutron emission of ${}^{133}$In. The level scheme of ${}^{132}$Sn is greatly expanded with the addition of 68 $\gamma$-transitions and 17 levels observed for the first time in the $\beta$ decay. The information on the excited structure is completed by new $\gamma$-transitions and states populated in the $\beta$-n decay of ${}^{133}$In. Improved delayed neutron emission probabilities are obtained both for ${}^{132}$In and ${}^{133}$In. Level lifetimes are measured via the Advanced Time-Delayed $\beta \gamma \gamma$(t) fast-timing method. An interpretation of the level structure is given based on the experimental findings and the particle-hole configurations arising from core excitations both from the \textit{N} = 82 and \textit{Z} = 50 shells, leading to positive and negative parity particle-hole multiplets. The experimental information provides new data to challenge the theoretical description of ${}^{132}$Sn.

   nucl-exPRC(2020)·16 citations
2. 02*

   Efficient emulators for scattering using eigenvector continuation

   R.J. Furnstahl🇺🇸 · A.J. Garcia🇺🇸 · P.J. Millican🇺🇸 · Xilin Zhang🇺🇸

   Eigenvector continuation EC has been shown to accurately and efficiently reproduce ground states for targeted sets of Hamiltonian parameters. It uses as variational basis vectors the corresponding ground-state eigensolutions from selected other sets of parameters. Here we extend the EC approach to scattering using the Kohn variational principle. We first test it using a model for S-wave nucleon-nucleon scattering and then demonstrate that it also works to give accurate predictions for non-local potentials, charged-particle scattering, complex optical potentials, and higher partial waves. These proofs-of-principle validate EC as an accurate emulator for applying Bayesian inference to parameter estimation constrained by scattering observables. The efficiency of such emulators is because the accuracy is achieved with a small number of variational basis elements and the central computations are just linear algebra calculations in the space spanned by this basis.

   ↳ nucl-thcond-mat.mtrl-scihep-lathep-ph+1PLB(2020)·80 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.