2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81665The properties of collective I^$Π$=1+ states in double even semimagic nucleus 140Ce are investigated in random phase approximation(RPA). The calculation of the B(M1) strength, elastic gamma-scattering cross section $σ_(gamma)(ω)$ and gamma-decay width $Σ_(gamma)(ω_i)$ show that in 140Ce the isovector spin-spin interactions concenrate the main strength of M1 transition at energy 7.89 MeV where the isovector spin-flip magnetic resonance may appear. The predisctions are consistent with the observed M1 strength in 140Ce which is seen to be concentrated within a range of about 0.8 MeV centered at an excitation of 7.95 MeV.6 pages, postscript onlyNuclear Theorytext