Neutron-proton pairing correlations in medium mass N≅Z nuclei

The pair structure and the average pairing gaps of realistic wave functions obtained within the complex Excited Vampir variational approach are investigated in order to evaluate the neutron-proton pairing correlations at low and high spins in medium mass N≅Z nuclei. The number of isovector Jπ=0+ pairs is calculated for the lowest few 0+ states in two chains of nuclei in the A≅70 mass region. The results indicate the dominant role played by the isovector neutron-proton pairing correlations in the structure of odd-odd N=Z nuclei and the reduction of their importance with increasing neutron excess in even-even nuclei. The evolution of particular isovector and isoscalar pairs with increasing angular momentum is analyzed for the odd-odd N=Z nucleus 74Rb and the even-even N=Z nucleus 72Kr. It turns out that in the nucleus 74Rb the neutron-proton correlations play an essential role for the alignment of the yrast positive-parity even-spin band