Rotational bands in ${}^{101–103}\mathrm{Nb}$ and ${}^{98,100}\mathrm{Y}$ nuclei and identification of yrast bands in ${}^{146}\mathrm{La}$ and ${}^{149}\mathrm{Pr}$

Several $\gamma$ transitions in ${}^{101–103}\mathrm{Nb},{\hspace{0.5em}}^{98,100}\mathrm{Y},{\hspace{0.5em}}^{146}\mathrm{La},$ and ${}^{149}\mathrm{Pr}$ are identified from spontaneous fission studies employing a ${}^{252}\mathrm{Cf}$ source and the Gammasphere detector array. In particular, the pairing-free bands in ${}^{100}\mathrm{Y}$ and ${}^{102}\mathrm{Nb}$ are extended, two rather highly deformed negative-parity bands feeding the 4.3-s $\beta$-decaying isomer of ${}^{102}\mathrm{Nb}$ are identified, and their possible bandhead configurations are discussed. In the case of ${}^{101,103}\mathrm{Nb},$ we have extended previously reported level schemes by over 20 transitions in each nuclide. For the fission partners ${}^{146}\mathrm{La}$ and ${}^{149}\mathrm{Pr}$ we have elucidated their previously unreported yrast level schemes.