Armenian Journal of Physics, 2010, vol. 3, issue 3, pp. 150-154 CHARACTER OF QUASI-BANDS IN 150 Sm USING IBM Rajesh Kumar 1* , Satendra Sharma 2 , and J.B. Gupta 3 1 Department of Physics, Noida Institute of Engineering & Technology, Greater Noida – 201306, India 2 Panchwati Institute of Engineering & Technology, Meerut- 250005, India 3 Ramjas College, University of Delhi, Delhi-110007, India * Email: rajeshkr0673@yahoo.co.in Received 15 June, 2010 Abstract: The interacting boson model-1 Hamiltonian is used to describe the energy spectrum for six quasi-bands in 150 Sm. In this work, g- , β-, and γ- bands in 150 Sm isotope are studied by using interacting boson model-1. It is found that the calculated energy values and B(E2) values have good agreement with experimental data. The calculated energy values and B(E2) values are also compared with the Dynamic Pairing-Plus-Quadrupole (DPPQ) Model. 1. Introduction The interacting boson model-1 (IBM-1) of Arima and Iachello [1] has been successful in describing the collective nuclear properties in the medium mass nuclei. Earlier systematic studies of 146-154 Sm have been performed using interacting boson model [2] and Dynamic Pairing-Plus- Quadrupole (DPPQ) Model [3,4,5]. Very recently Diab [6] presented electrical monopole transition structure of 150 Sm isotope. Simpson et al. [7] successfully interpreted the isomers of 156,158 Sm using Quasi-particle Rotor Model. Sharma and Kumar [8] presented a fresh analysis of g- , β-, and γ- bands in 150 Sm using IBM. This search is now extended to calculate B(E2) values for (g --> g), (β --> g) , (β --> β), (γ --> g) and (γ --> β ) transitions using IBM and compare with experimental data [9,10]. The study of quasi-bands in 150 Sm has not been studied sufficiently, thus the present study is interesting to investigate. Recent experimental data of energies have been taken from the website of National Nuclear Data center, Brookhaven National Laboratory, USA [16]. 2. The Interacting Boson Model The phenomenological Interacting Boson Model –1 (IBM-1) initially introduced by Arima and Iachello [1] has been rather successful in describing the collective properties of several medium and heavy mass nuclei. In the first approximation, only pairs with angular momentum L = 0 (called s-bosons) and L = 2 (called d-bosons) are considered. The model has associated with it an inherent group structure, which allows for the introduction of limiting symmetries called SU(5), SU(3) and O(6). However, in a more general case the full IBM-1 Hamiltonian has to be used, which has several forms [1]. The multi-pole form of the interacting boson model-1 Hamiltonian is given by ( ) ( ) ( ) ( ) ( ) 0 1 2 3 3 3 4 4 4 ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ . . . . . , d H n a P P a LL a QQ a TT a T T + =ε + + + + + where the interaction parameters in the PHINT Program are given below: ε = EPS, 0 2PAIR, a = 1 ELL 2, a = 2 QQ 2, a = 3 5OCT a = and 4 5HEX. a =