arXiv subjects

C. Dariescu

Publications and source records attributed to C. Dariescu.

4 recordsLinked to original sources

arXiv2011

Fermion confinement induced by geometry

We consider a five-dimensional model in which fermions are confined in a hypersurface due to an interaction with a purely geometric field. Inspired by the Rubakov-Shaposhnikov field-theoretical model, in which massless fermions can be localized in a domain wall through the interaction of a scalar field, we show that particle confinement may also take place if we endow the five-dimensional bulk with a Weyl integrable geometric structure, or if we assume the existence of a torsion field acting in the bulk. In this picture, the kind of interaction considered in the Rubakov-Shaposhnikov model is replaced by the interaction of fermions with a geometric field, namely a Weyl scalar field or a torsion field. We show that in both cases the confinement is independent of the energy and the mass of the fermionic particle. We generalize these results to the case in which the bulk is an arbitrary n-dimensional curved space.

gr-qc↗

arXiv2004

CP violating SUSY effects in Penguin dominated modes B -> PHI K and B -> PHI K*

Recent measurement of time dependent asymmetries in $B \to ϕK$ are indicative of a new source of CP violation. We examine squark mixing in SUSY as this new source, and using QCD improved factorization method to describe $B \to ϕK $ decay, find the allowed range of parameter space for $ρ$ and $ψ$, the magnitude and phase of the down type LR(RL) squark mixing parameter $δ^{bs}_{LR(RL)}$. We then study $B \to ϕK^{*}$ and calculate the expected CP asymmetries in the same range of parameter space. We find that this asymmetry is in the range 15% to $20% $ for acceptable value of $B \to phi K^{*}$ branching ratio. We also predict the helicity dependent CP asymmetries in the same parameter space.

hep-ph↗

arXiv1995

Perturbative QCD estimation of the $B \to K^{*} + γ$ branching ratio

Working in a perturbative QCD model approach, we obtain the essential form factor of the radiative transition $B \rightarrow V^{*} γ$ and estimate the branching ratio $BR(B \rightarrow K^{*} γ)$. 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.

hep-ph↗

arXiv1995

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.

gr-qc↗