One-phonon 2{sub 1,ms}{sup +} mixed-symmetry state of {sup 148}Sm observed in nuclear resonance fluorescence

To search for the 2{sub 1,ms}{sup +} state of {sup 148}Sm, we studied the {sup 148}Sm({gamma},{gamma}{sup '}) photon scattering reaction at the Stuttgart Dynamitron accelerator using bremsstrahlung with an endpoint energy of 3.2 MeV. Nuclear resonance fluorescence from eleven excited states, including three 2{sup +} states, between 1.4 and 3.1 MeV has been observed. The data allow the identification of the 2{sub 5}{sup +} state at 2146 keV as the 2{sub 1,ms}{sup +} state of {sup 148}Sm.