Estimates of the isospin-violating Λb- Σ0φ;Σ0J=ψ decays and the Σ - Λ mixing

We analyze the two purely isospin-violating decays A(b) -E-0 phi and A(b) -E(0)J=psi, proceeding merely via the exchange topologies, in the framework of the perturbative QCD approach. Assuming E0 baryon belongs to the idealized isospin triplet with quark components of usd, the branching ratios of the two decay modes are predicted to be tiny, of the order 10(-8) - 10(-9), leading to difficulty in observing them. We then extend our study to include the Sigma - A mixing. It is found that the mixing has significant effect on the Ab -Sigma decays, especially it can greatly increase the rate of the J=psi process, by as much as two orders of magnitude, yield 10-7, which should be searchable in the future. We also estimate a set of asymmetry observables with and without the mixing effect, which will be tested in coming experiments.

Automated summary

In this study, we analyze two purely isospin-violating decays and find that their branching ratios are very small, making it difficult to observe them. Furthermore, we investigate the effect of Sigma - A mixing on a specific decay process, which will be tested in future experiments.