Updated analysis of the Er-170(p, t)Er-168 reaction data

More than 200 states up to 4.1 MeV excitation have been populated in 168Er with the 170Er(p, t) reaction at 25 MeV incident energy. About 80 of these states, with 0+ and 2+ assignments, were reported in a previous publication [D. Bucurescu et al., Phys. Rev. C 73, 064309 (2006)]. The present work considerably enriches the knowledge of this nucleus. A multistep coupled-channels analysis of the angular distributions is now presented for all the states observed in this experiment. Spin and parity values between 0+ and 7- are newly assigned for more than 100 states. For the states already reported in the ENSDF database with J & pi; values there is a good agreement with our values. The 168Er nucleus remains one of the best experimentally known nuclei for states with low and medium spins below 4 MeV excitation energy, representing a challenge for future microscopic structure model calculations aiming to disentangle the contributions of different excitation degrees of freedom.

Automated summary

More than 200 states up to 4.1 MeV excitation have been observed in 168Er with the 170Er(p, t) reaction at 25 MeV incident energy. A multistep coupled-channels analysis has been conducted for all the states to determine their spin and parity values, leading to the assignment of more than 100 newly determined values. The results show good agreement with previously reported values in the ENSDF database, making 168Er a well-known nucleus for low and medium spin states.