Collective Properties of Odd-Odd N = Z Nuclei and Sum Rule for Isovector m1 Transitions

Isovector ΔT = 1 M1 transitions between low-lying states in deformed odd-odd N = Z nuclei are discussed. The explicit expressions for B(M1) values derived in the frames of rotor-plus-quasideuteron model help to establish simple regularities for M1 strengths, to determine spin and orbital contributions to the total strength, and to get sum rule. The theoretical results are illustrated by very recent experimental data.