CALCULATION OF FORM FACTORS AND SEMI-LEPTON BRANCHINGS OF THE B → ρ TRANSITION IN THE COVARIANT QUARK MODEL

Abstract

In this paper, we study the   transition in the framework of the covariant confined quark model. The covariant confined quark model is a quantum field approach to hadron interactions based on the Lagrangian of the interaction of hadrons interacting with their constituent quarks. An important difference from other theoretical models is that the numerical results (form factors, branchings, widths and angular observables) are calculated over the entire kinematic range of the transferred momentum . The   transition is a subject of interest in high energy physics. Form factors and branchings have been obtained in different theoretical approaches. Experimentalists from the LHCb collaboration plan to measure this decay in the future, since this transition occurs with a changing flavor of neutral current. In this work we have calculated the form factors for the   transition over the entire kinematic range of the transferred momentum . We have compared the numerical results from our model with the predictions of other theoretical approaches. We have converted our form factors into the Bauer-Stech-Wirbel (BSW) form factors for comparison with other theoretical approaches. The theoretical predictions are in satisfactory agreement with each other. Using these form factors we have calculated the branchings for the semileptonic decay , where  are leptons. We have plotted the behavior of the form factors and branchings as functions of the squared momentum transfer. The results obtained in this work have demonstrated a high degree of agreement with the predictions of other theoretical models such as the light-cone sum rules, lattice quantum chromodynamics, and the relativistic quark model. This confirms the reliability and accuracy of the covariant confined quark model for studying rare decays involving heavy quarks.