The nuclear structure of the semi-magic isotope ${}^{125}\mathrm{Sn}$ was investigated by means of the ${}^{124}\mathrm{Sn}$($n$${}_{\mathrm{th}}$,$\gamma \gamma$)${}^{125}\mathrm{Sn}$ reaction and the ${}^{124}\mathrm{Sn}$($\mathrm{d⃗}$,$p$)${}^{125}\mathrm{Sn}$ reaction. More than 400 levels, in most cases with their spin, parity, ($d,p$) spectroscopic factor, and $\gamma$ decay, were identified. About 750 $\gamma$ transitions from our ($n,$$\gamma \gamma$) experiment form the essentially complete $\gamma$-decay scheme following thermal neutron capture. Using this extensive $\gamma$-decay scheme the neutron binding energy was determined to be 5733.5(2) keV. The strong correlation of the ($d,p$) strengths and the ($n$,$\gamma$) intensities for more than 50 levels gives evidence for the direct neutron capture process, which was studied in detail. The experimental data were compared with predictions of the quasiparticle phonon model.

• Received 12 August 2009

DOI:https://doi.org/10.1103/PhysRevC.83.044326