Shell model for rotation-like spectra of Sr isotopes

The isotopes of Sr are described by a shell-model with the proton-neutron configurations $\text{(2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, 2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{, 1}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)}{}_{\mathrm{<mtext>p</mtext>}}{}^{\mathrm{?2}}\text{× (1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}_{\mathrm{<mtext>n</mtext>}}{}^{\mathrm{?(50?N)}}$. The transition of the spectrum from a shell structure to a rotation-like structure which is experimentally observed in the Sr isotopes can be reproduced by the present model.