Triptesh De

We calculate the decay width for $\Lambda_b \to \Lambda_c e {\bar \nu}$ in the frame work of a nonrelativistic quark (NRQ) model of heavy baryons where the light quarks play the role of spectators. Our calculation does not make an explicit…

In the context of the observed decay $B \rightarrow K^* \gamma$ the applicability of the Heavy Quark Effective Theory (HQET), treating both b and s as heavy quarks, is examined. We show that the heavy s-quark approximation, as can be found…

We derive a theoretically allowed domain for the charge radius $\rho$ and curvature $c$ of the Isgur-Wise function describing the decay $\Lambda_b \to \Lambda_c l {\bar \nu_l}$. Our method uses crossing symmetry, dispersion relations and…

Qualitative changes in the collective excitation spectra of the $\rho$-meson triplet in neutron matter is studied, with particular emphasis on the breaking of the discrete $p\leftrightarrow n$ symmetry. The appearance of additional branches…

The effects of magnetic interaction between vector mesons and nucleons on the propagation (mass and width) of the $\rho$-meson in particular moving through very dense nuclear matter is studied and the modifications, qualitative and…

The running of the $\rho\bar N N$ couplings in presence of nuclear matter is studied, and the relevant $\beta$-functions are shown to be different for $\rho^0$ and $\rho^+$, when the nuclear medium is asymmetric.