First observation of the decay of a 15−seniorityv=4isomer in

S. Piétri¹,

A. Jungclaus²,

M. Górska³

et al.

Abstract

Isomeric states in the semimagic [128][129][130] Sn isotopes were populated in the fragmentation of a 136 Xe beam on a 9 Be target at an energy of 750 A·MeV. The decay of an isomeric state in 128 Sn at an excitation energy of 4098 keV has been observed. Its half live has been determined to be T 1/2 = 220(30) ns from the time distributions of the delayed γ rays emitted in its decay. γ γ coincidence relations were analyzed in order to establish the decay pattern of the newly established state toward the known (7 − ) and (10 + ) isomers at excitation energies of 2092 and 2492 keV, respectively. Based on a comparison with results of state-of-the-art shell-model calculations the new isomeric state is proposed to have the νh

High-spin states with seniorityv=4, 5, and 6 in119–126Sn

“…During the completion of this work, the decay of a new isomeric state in 128 Sn populated in the fragmentation of 136 Xe was reported [9]. Its de-excitation is very similar to that of the isomeric states we have measured in 120-126 Sn.…”

“…the high-spin long-lived states of heavy In [2][3][4][5][6][7][8]. During the completion of the present work, the decay of a new isomeric state in 128 Sn populated in the fragmentation of 136 Xe has been reported [9], and this has been proposed to be the 15 − state expected from the (νh 11/2 ) −3 (νd 3/2 ) −1 configuration.…”

“…. (Color online) Evolution of the highest-spin states of the even-A Sn isotopes, as a function of the mass number (this work and Ref [9]. for 128 Sn).…”

Monopole-optimized effective interaction for tin isotopes

“…The largest difference is seen in the 3/2 + 1 state in 115 Sn mentioned above, where the experimental data are underestimated by [17,18,76]. In Fig.…”

“…6. (Color online) Experimental[17,18,67,76] (open symbols) and calculated (solid symbols with dotted lines) excitation energies of the low-lying even spin states in nuclei 102−130 Sn.…”