Microscopic description of g factors and M1 properties in platinum isotopes

Starting from the shell model configurations, valence nucleon effective int eractions and fermion M1 transition current density operator, the counterpa rts in the proton-neutron interacting boson model (sdIBM-2) of the fermion Hamiltonian and M1 transition current density operator are derived microsco pically with the help of Dyson expansion technique. The boson g factors are abstracted from the boson M1 transition current density operator. Spectra, g factors of 2(1)(+), 2(2)(+), 4(1)(+) states and M1 matrix elements betwe en 2(2)(+) and 2(1)(+) are calculated for the even Pt192-198 isotopes in th e sdIBM-2. The theoretical results fit experimental data quite well.