arXiv subjects

Triptesh De

Publications and source records attributed to Triptesh De.

6 recordsLinked to original sources

arXiv1998

Dispersive Bounds on The Shape Of Lambda_b to Lambda_c l {\bar ν_l} Formfactors

We derive a theoretically allowed domain for the charge radius $ρ$ and curvature $c$ of the Isgur-Wise function describing the decay $Λ_b \to Λ_c l {\bar ν_l}$. Our method uses crossing symmetry, dispersion relations and analyticity in the context of the Heavy Quark Effective Theory but is independent of the specifics of any given model. The experimentally determined values of the $Υ$ masses have been used as input information. The results are of interest for testing different models employed to calculate the heavy baryon formfactors which are used for the extraction of $| V_{cb} |$ from the experimental data.

hep-ph↗

arXiv1996

Non-relativistic Model for the Semileptonic Λ_b \to Λ_c Decay

We calculate the decay width for $Λ_b \to Λ_c e {\bar ν}$ 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 use of the heavy quark symmetry. The branching ratio for the above process as calculated here agrees reasonably well with the experimental value.

hep-ph↗

arXiv1996

Applicability of Heavy Quark Effective Theory to the Radiative Decay $B\to K^* + γ$

In the context of the observed decay $B \rightarrow K^* γ$ 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 in the literature, is not reliable.

hep-ph↗

arXiv1996

Rho Mesons in Asymmetric Nuclear Matter: A Renormalization Group Approach

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

nucl-th↗

arXiv1995

Symmetry Breaking for Rho Meson in Neutron Matter

Qualitative changes in the collective excitation spectra of the $ρ$-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 in the dispersion characteristics, the mass splitting among the charge states, the splitting between longitudinal and transverse modes of the $ρ^{\pm}$ mesons and the appearance of `island' modes (or loops) in the time-like region are some of the features that are exposed.

nucl-th↗

arXiv1995

Tensor Coupling and Vector Mesons in Dense Nuclear Matter

The effects of magnetic interaction between vector mesons and nucleons on the propagation (mass and width) of the $ρ$-meson in particular moving through very dense nuclear matter is studied and the modifications, qualitative and quantitative, due to the relevant collective modes (zero-sound and plasma frequencies) of the medium discussed. It is shown that the $ρ$-mesons produced in high-energy nuclear collisions will be longitudinally polarized in the region of sufficiently dense nuclear matter, in the presence of such an interaction.

nucl-th↗