Weak Decays of Doubly Heavy Baryons: the $1/2\to 1/2$ case

TL;DR

This paper studies the weak decay processes of doubly heavy baryons into spin 1/2 states, deriving form factors and predicting decay widths to guide future experimental investigations.

Contribution

It provides the first calculation of hadronic form factors for these decays using the light-front approach, offering predictions for decay widths of various doubly heavy baryons.

Findings

Several decay channels have sizable partial widths.

Predictions are made for semi-leptonic and non-leptonic decay rates.

Results can be tested at LHC, Belle II, and CEPC.

Abstract

Very recently, the LHCb collaboration has observed in the final state $\Lambda_c^+ K^-\pi^+\pi^+$ a resonant structure that is identified as the doubly-charmed baryon $\Xi_{cc}^{++}$. Inspired by this observation, we investigate the weak decays of doubly heavy baryons $\Xi_{cc}^{++}$, $\Xi_{cc}^{+}$, $\Omega_{cc}^{+}$, $\Xi_{bc}^{(\prime)+}$, $\Xi_{bc}^{(\prime)0}$, $\Omega_{bc}^{(\prime)0}$, $\Xi_{bb}^{0}$, $\Xi_{bb}^{-}$ and $\Omega_{bb}^{-}$ and focus on the decays into spin $1/2$ baryons in this paper. At the quark level these decay processes are induced by the $c\to d/s$ or $b\to u/c$ transitions, and the two spectator quarks can be viewed as a scalar or axial vector diquark. We first derive the hadronic form factors for these transitions in the light-front approach and then apply them to predict the partial widths for the semi-leptonic and non-leptonic decays of doubly heavy baryons. We find that a number of decay channels are sizable and can be examined in future measurements at experimental facilities like LHC, Belle II and CEPC.