Fermionic-bosonic couplings in a weakly-deformed odd-mass nucleus, $^{93}_{41}$Nb

TL;DR

This study constructs a detailed decay scheme of $^{93}$Nb, identifying fermionic-bosonic excitations and providing a microscopic interpretation through shell-model calculations, enhancing understanding of nuclear structure in this isotope.

Contribution

It offers the first comprehensive decay scheme of $^{93}$Nb below 2 MeV, identifying fermionic-bosonic excitations and interpreting them with advanced shell-model calculations.

Findings

Identification of isoscalar and isovector fermionic-bosonic excitations.

Determination of branching ratios, lifetimes, and transition multipolarities.

Shell-model calculations support the experimental interpretation.

Abstract

A comprehensive decay scheme of $^{93}$Nb below 2 MeV has been constructed from information obtained with the $^{93}$Nb(n,n$^\prime$$\gamma$) and $^{94}$Zr(p,2n$\gamma$$\gamma$)$^{93}$Nb reactions. Branching ratios, lifetimes, transition multipolarities and spin assignments have been determined. From $M1$ and $E2$ strengths, fermionic-bosonic excitations of isoscalar and isovector character have been identified from the weak coupling $\pi1g_{9/2}$$\otimes$$^{92}_{40}$Zr and $\pi2p_{1/2}^{-1}$$\otimes$$^{94}_{42}$Mo configurations. A microscopic interpretation of such excitations is attained from shell-model calculations using low-momentum effective interactions.