Weak decays of heavy baryons in the light-front approach**Supported by National Natural Science Foundation of China (11575110, 11655002, 11735010) and Natural Science Foundation of Shanghai (15DZ2272100)

Zhen-Xing Zhao

doi:10.1088/1674-1137/42/9/093101

Abstract

In this work, we analyse semi-leptonic and non-leptonic weak decays of the heavy baryons: Λb, Ξb, Ωb and Λc, Ξc, Ωc. For non-leptonic decay modes, we study only the factorizable channels induced by the external W-emission. The two spectator quarks in the baryonic transitions are treated as a diquark and form factors are calculated in the light-front approach. Using the results for form factors, we also calculate some corresponding semi-leptonic and non-leptonic decay widths. We find that our results are comparable with the available experimental data and other theoretical predictions. Decay branching fractions for many channels are found to reach the level 10−3 ∼ 10−2, which is promising for discovery in future measurements at BESIII, LHCb and Belle II. The SU(3) symmetry in semi-leptonic decays is examined and sources of symmetry breaking are discussed.

Highlights

Quite recently, the LHCb collaboration announced the discovery of the doubly charmed baryon Ξ+cc+ [1]
There are rapid progresses in the study of Λc decays at BESIII [22,23,24,25,26,27] and some recent studies on Λb and Λc decays by LHCb can be found in Refs. [28,29,30,31,32,33]
We have presented the explicit expressions of form factors

Summary

INTRODUCTION

The LHCb collaboration announced the discovery of the doubly charmed baryon Ξ+cc+ [1] This discovery will open a new door to study strong interactions in the presence of a pair of heavy quarks. Light flavor SU(3) symmetry arranges the singly heavy baryons into the presentations 3 ⊗ 3 = 6 ⊕ 3 ̄, as can be seen from Fig. 1. The light baryons in the final state are composed of 3 light quarks and belong to the baryon octet Their wave functions, including the flavor and spin spaces, have the form [34]. Some recent works have been devoted to investigate the singly heavy baryon decays with the help of flavor SU(3) symmetry [79,80,81,82]. A brief summary will be given in the last section

THEORETICAL FRAMEWORK

Form factors

Spin and flavor wave functions

NUMERICAL RESULTS AND DISCUSSIONS

Inputs

Semi-leptonic results

Non-leptonic results

Uncertainties

CONCLUSION

Wave functions in the standard flavor-spin basis

Wave functions in the diquark basis