Study of Multiphonon $\gamma\gamma$-Band Through Modified Soft Rotor Formula

The structure of multiphonon $\gamma\gamma$-band of $^{156}Gd$ is investigated by using the Modified Soft Rotor Formula (MSRF). The Modified Soft Rotor Formula proposed by Gupta et al. [1] is given as: \begin{equation} E(I)=EK + \frac{\hbar^{2} I(I+1)}{2\theta(1+ \sigma I)}, \end{equation} where $\theta$ is moment of inertia, $\sigma$ is known as softness parameter and $EK$ is constant energy term. The calculated values of moment of inertia of $\gamma\gamma$-band are almost equal to the moment of inertia of $\gamma$-band. The study of K=2 $\gamma$-band and K=4 $\gamma\gamma$-band using MSRF yield good energy values. The small values of the softness parameter and positive values of moment of inertia are obtained for multiphonon band. The staggering pattern in $\gamma$-band and $\gamma\gamma$-band are also studied. Recently, the study of multiphoon $\gamma\gamma$-band in $^{112}Ru$ and isotopes of $Mo$ have been done by Kumari and Mittal [2]. \\[4pt] [1] J. B. Gupta, S. Sharma and V. Katoch, Pramana J. of Phys., 81, 75 (2013).\\[0pt] [2] Parveen Kumari and H.M. Mittal, Physica Scripta (2015) In Press.