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Large scale shell model calculations have been carried out for odd-odd 58−62 Mn isotopes in two different model spaces. First set of calculations have been carried out in full fp shell valence space with two recently derived fp shell interactions namely GXPF1A and KB3G treating 40 Ca as core. The second set of calculations have been performed in f pg 9/2 valence space with the f pg interaction treating 48 Ca as core and imposing a truncation by allowing up to a total of six particle excitations from the 0f 7/2 orbital to the upper fp orbitals for protons and from the upper fp orbitals to the 0g 9/2 orbital for neutron. For low-lying states in 58 Mn, the KB3G and GXPF1A both predicts good results and for 60 Mn, KB3G is much better than GXPF1A. For negative parity and high-spin positive parity states in both isotopes f pg interaction is required. Experimental data on 62 Mn is sparse and therefore it is not possible to make any definite conclusions. More experimental data on negative parity states is needed to ascertain the importance of 0g 9/2 and higher orbitals in neutron rich Mn isotopes.

Heavy quark systems ( cc and bb ) have been studied in the nonrelativistic framework using energy dependent interquark potential of the form harmonic oscillator with a small linear term as energy dependent as perturbation plus a inverse square potential. This potential admits exact analytical solution of the Schrodinger equation. Mass spectra, leptonic decay width, root mean square radii   2 r , the expectation value of the radius   r and 1 r have been estimated for different quantum mechanical states for cc and bb systems. It is observed that energy dependent term in the potential leads to saturation of the mass spectra and degree of saturation is governed by the magnitude of perturbation. The calculated values of leptonic decay widths for 1s state are in very good agreement with the experimental data both for cc and bb systems.

The recently measured experimental data of Legnaro National Laboratories on neutron rich even isotopes of 62−66 Fe with A=62,64,66 have been interpreted in the framework of large scale shell model. Calculations have been performed with a newly derived effective interaction GXPF1A in full fp space without truncation.The experimental data is very well explained for 62 Fe, satisfactorily reproduced for 64 Fe and poorly fitted for 66 Fe. The increasing collectivity reflected in experimental data when approaching N=40 is not reproduced in calculated values. This indicates that whereas the considered valence space is adequate for 62 Fe, inclusion of higher orbits from sdg shell is required for describing 66 Fe.

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