Two-phonon 1^{-} state in ^{112}Sn observed in resonant photon scattering

Results of a photon scattering experiment on Sn-112 using bremsstrahlung with an endpoint energy of E-0=3.8 MeV are reported. A J=1 state at E-x=3434(1) keV has been excited. Its decay width into the ground state amounts to Gamma(0)=151(17) meV, making it a candidate for a [2(+)circle times 3(-)]1(-) two-phonon state. The results for Sn-112 are compared with quasiparticle-phonon model calculations as well as the systematics of the lowest lying 1(-) states established in other even-mass tin isotopes. In contrast to findings in the heavier stable even-mass Sn isotopes, no 2(+) states between 2 and 3.5 MeV excitation energy have been detected in the present experiment.