Purely collective versus RPA rotational vibrations

Abstract

The low-lying 1 + isovector state |RPA〉 in 48Ti is calculated in RPA removing the spurious state due to rotations. Its excitation energy, the magnetic dipole transition B(M1; 0 +→1 +) and the (e, e′) form factors are compared with experiment, with the purely collective scissor vibration of the deformed protons against the deformed neutrons | ROT〉=N(a n J x n −a p J x p )|〉 and with the purely orbital state | ORB〉=N L (b n L x n −b p L p )|〉 . Although the collective states overlap only by |〈ROT|RPA〉| 2=0.12 and |〈ORB|RPA〉| 2=0.07, the μ=±1 residual quadrupole force is generated in RPA scissor type isovector rotational vibrations, but only very few nucleons are participating.