Inverted Spin Sequences in the Spectra of Odd-Odd Nuclei in the 2S-1d and 2P-1f Shells

Abstract

In case of odd-odd nuclei, near magic numbers, there are found inverted sequences as well as few rotational members. In order to explain the unique feature of the spectra of odd-odd nuclei, we have applied modified form of rotational-vibrational model with two parameters A and B. It is found that level orders in inverted as well as in rotational sequences are very well reproduced on the basis of this model. In case of inverted spin sequences, the sign of B is found to be positive. The ratio of B⁄A is ≈10⁻² as compared to its value of the order of 10⁻³ in case of even-even & odd—A nuclei. We infer that pair correlations are responsible for these invertions. The simple model applied here worked well to predict these inverted spectra.