Exclusive semileptonic and nonleptonic $J/\psi$ decays

TL;DR

This paper calculates the decay probabilities of $J/ar{psi}$ particles into leptons and hadrons using a relativistic quark model, providing theoretical predictions for these rare processes.

Contribution

It offers a comprehensive calculation of form factors and decay branching fractions for $J/ar{psi}$ decays within a relativistic framework, including relativistic effects.

Findings

Branching fractions for semileptonic decays are estimated to be between 10^{-9} and 10^{-12}.

Form factors are expressed as overlap integrals of meson wave functions across the entire kinematic range.

Results are compared with previous theories and experimental bounds.

Abstract

Exclusive semileptonic and nonleptonic $J/\psi$ decays are investigated in the framework of the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The form factors parameterizing the hadronic matrix element of the weak current are calculated with the complete account of the relativistic effects. These form factors are expressed as the overlap integrals of the meson wave functions and are determined in the whole accessible kinematic range. On this basis the semileptonic decay branching fractions are evaluated for decays involving both electrons and muons. The nonleptonic decays are considered in the factorization approximation in the limit for the number of colors $N_c\to \infty$. The obtain branching fractions are found to be of the order $10^{-9}\sim 10^{-12}$. They are compared with the previous theoretical predictions and available experimental upper bounds.