Phys.Lett. B 829, 137129 (2022)

W.Q.Zhang, A.N.Andreyev, Z.Liu, D.Seweryniak, H.Huang, Z.H.Li, J.G.Li, C.Y.Guo, D.T.Doherty, A.E.Barzakh, P.Van Duppen, J.G.Cubiss, B.Andel, S.Antalic, M.Block, A.Bronis, M.P.Carpenter, P.Copp, B.Ding, Z.Favier, F.Giacoppo, T.H.Huang, X.H.Yu, B.Kindler, F.G.Kondev, T.Lauritsen, G.S.Li, B.Lommel, H.Y.Lu, M.Al Monthery, P.Mosat, Y.F.Niu, C.Raison, W.Reviol, G.Savard, S.Stolze, G.L.Wilson, H.Y.Wu, Z.H.Wang, F.R.Xu, Q.B.Zeng, X.H.Zhou

First observation of a shape isomer and a low-lying strongly-coupled prolate band in neutron-deficient semi-magic ¹⁸⁷Pb

NUCLEAR REACTIONS ¹⁴²Nd(⁵⁰Cr, 3n2p)¹⁸⁷Pb, E=255 MeV beam from ATLAS-ANL facility, followed by separation of evaporation residues (EVRs) using Argonne Gas-Filled Analyzer; measured Eα, Eγ, Iγ, x rays, αγ-coin, γγ-coin, T_1/2 of a new low-energy microsec-isomer by αγ(t) using Gammasphere for γ detection and double-sided silicon strip detector (DSSD) for EVRs and α particles. Recoil-decay tagging (RDT) and isomer-decay tagging (IDT) methods. ¹⁸⁷Pb; deduced high-spin levels, J, π, isomer, K-conversion coefficient, multipolarity, bands, B(E2), B(M1)/B(E2), triple-shape coexistence at low energy. Comparison with band structure in ¹⁸⁵Hg. Systematics of aligned angular momenta plots and experimental Routhians for bands in ^183,185Hg, ¹⁸⁷Pb. ¹⁸⁴Hg, ¹⁸⁶Pb, ¹⁸⁷Tl; observed γ rays. ^186,187m,188Pb; observed α-decay peaks.

doi: 10.1016/j.physletb.2022.137129