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

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 $\pi 1g_{9/2}$$\otimes$${}_{40}^{92}$Zr and $\pi 2p_{1/2}^{-1}$$\otimes$${}_{42}^{94}$Mo configurations. A microscopic interpretation of such excitations is attained from shell-model calculations using low-momentum effective interactions.

Comments: 13 pages, 5 figures