Semileptonic Decays of Heavy Baryons in the Relativistic Quark Model

Rudolf N Faustov,Vladimir O Galkin

doi:10.3390/particles3010017

Abstract

Semileptonic and rare semileptonic decays of heavy baryons are studied in the framework of the relativistic quark model based on the quark-diquark picture, quasipotential approach, and quantum chromodynamics (QCD). The form factors parametrizing the matrix elements of the weak transitions are calculated in the whole accessible kinematical range with the comprehensive account of the relativistic effects. The obtained results for the branching ratios and other observables agree well with the available experimental data.

Highlights

In recent years significant experimental progress has been achieved in studying decays of heavy baryons
Semileptonic and rare semileptonic decays of heavy baryons are studied in the framework of the relativistic quark model based on the quark-diquark picture, quasipotential approach, and quantum chromodynamics (QCD)
Using Equation (4) for the decay matrix element of the weak current the form factors are expressed as overlap integrals of baryon wave functions. (The spin-flavour structure of the wave functions of the members of the light baryon octet in the quark-diquark model is given in Ref. [11].) Contribution both of leading Γ(1) and subleading order Γ(2) vertex functions as well as relativistic transformation of the baryon wave function form the rest to moving reference frame are taken into account

Summary

Introduction

In recent years significant experimental progress has been achieved in studying decays of heavy baryons. Weak decays of heavy baryons can serve as an additional source for the determination of the Cabbibo-Kobayashi-Maskawa (CKM) matrix elements. It is important to remember that the diquark inside a baryon is composed of two quarks It is not a point-like object and its interaction with gluons is smeared by the form factor which can be expressed through the overlap integral of diquark wave functions. On the basis of the relativistic quark model the explicit expressions for the decay form factors were obtained in terms of the overlap integrals over the baryon wave functions which are known from their mass spectrum calculations [8,9]. Good agreement of theoretical results with experimental data is found

Relativistic Quark Model

Semileptonic Decay form Factors

Bottom Baryon Decays

Charm Baryon Decays

Rare Radiative Λb Baryon Decay

Conclusions