Perturbative QCD estimation of the B→K∗+γB \to K^{*} + \gamma branching ratio

Working in a perturbative QCD model approach, we obtain the essential form factor of the radiative transition $B \rightarrow V^{*} \gamma$ and estimate the branching ratio $BR(B \rightarrow K^{*} \gamma)$. The results are determined by a parameter expressing the momentum distribution in the $B$ - meson wave function. Our estimations are compared to other theoretical predictions as well as to experimental data.Comment: 8 pages, Figure is not include

Axially symmetric stars in Einstein-Maxwell theory

In this work we show how to construct general relativistic star models with axial symmetry in the Einstein-Maxwell theory. Starting with a general axially symmetric interior fluid solution we show how to construct the corresponding electrically charged and also the corresponding magnetized solution of the Einstein-Maxwell-fluid equations. As an example, we provide an electrically charged version of the anisotropic Bower and Liang solution.Comment: 9 pages, no figures. v2. corrected an incorrect statement in section 2.1. Updated list of references. arXiv admin note: text overlap with arXiv:1804.0807

A Toy Model Approach to the Canonical Non-perturbative Quantization of the Spatially Flat Robertson-Walker Spacetimes with Cosmological Constant

We present a toy model approach to the canonical non-perturbative quantization of the spatially-flat Robertson-Walker Universes with cosmological constant, based on the fact that such models are exactly solvable within the framework of a simple Lagrangian formulation. The essential quantum dynamical metric-field and the corresponding Hamiltonian, explicitly derived in terms of annihilation and creation operators, point out that the Wheeler - DeWitt equation is a natural (quantum) generalization of the $G_{44}$ - Einstein equation for the classical De Sitter spacetime and selects the physical states of the quantum De Sitter Universe. As a result of the exponential universal expansion, the usual Fock states (defined as the eigenstates of the number-operator) are no longer invariant under the derived Hamiltonian. They exhibit quantum fluctuation of the energy and of the metric field which lead to a (geometrical) volume quantization.Comment: 22 pages, LaTe

Perturbative QCD analyses of the nonleptonic BB meson decays

Based on Brodsky-Lepage approach, the nonleptonic $B$ meson decay branching ratio is derived in terms of three parameters and is geometrically analysed as the 3-surface embedded in the 4-dimensional (abstract) Euclidean space generated by the three parameters and $BR$. Investigating its 2-dimensional sections, we find ranges for these parameters imposed by a comparison with experimental data.Comment: 13 pages, LaTeX format, figures not include