Systematic study of rotational energy formulae for superdeformed bands in La and Ce isotopes

The experimental rotational spectra of superdeformed (SD) bands of La-130, Ce-131(1,2), (132) Ce(1,2,3) and Ce-133(1,2,3) in the A similar to 130 mass region are systematically analyzed with the four parameter formula, power index formula, nuclear softness formula, and VMI model. It is observed that out of all the formulae, the four parameter formula suits best for the study of the La-130, Ce-131(1,2), Ce-132(2,3) and Ce-133(1,2,3) SD bands. The four parameter formula works efficiently in determining the band head spin of the La-130, Ce-131(1,2) Ce-132(2,3) and Ce-133(1,2,3) SD bands. Good agreement is seen between the calculated and observed transition energies whenever the accurate spin is assigned. In Ce-132(1), the power index formula is found to work better than the other three formulae. The dynamic moment of inertia is also calculated for all the formulae and its variation with the rotational frequency is investigated.