Mirrored one-nucleon knockout reactions to the T-z = +/- 3/2 A=53 mirror nuclei

Abstract

Background: The study of excited states in mirror nuclei allows us to extract information on charge-dependent (i.e., isospin-nonconserving) interactions in nuclei.

Purpose: To extend previous studies of mirror nuclei in the f72 region, investigating charge symmetry breaking of the strong nuclear force.

Methods: γ-ray spectroscopy has been performed for the mirror (Tz=±32) pair Ni53 and Mn53, produced via mirrored one-nucleon knockout reactions.

Results: Several new transitions have been identified in Ni53 from which a new level scheme has been constructed. Cross sections for knockout have been analyzed and compared with reaction model calculations where evidence is found for knockout from high-spin isomeric states. Mirror energy differences between isobaric analog states have been computed, compared to large scale shell-model calculations, and interpreted in terms of isospin-nonconserving effects. In addition, lifetimes for the long-lived Jπ=52−1 analog states in both Mn53 and Ni53 have been extracted through lineshape analysis, giving half-lives of t12=120(14) ps and t12=198(12) ps, respectively.

Conclusions: The inclusion of a set of isovector isospin-nonconserving matrix elements to the shell-model calculations gave the best agreement with the experimental data. Show more