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arXiv · 2308.02262

Estimates of the isospin-violating $Λ_b\rightarrow Σ^0 ϕ, Σ^0 J/ψ$ decays and the $Σ-Λ$ mixing

Zhou Rui·Jia-Ming Li·Chao-Qi Zhang
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Abstract

We analyse the two purely isospin-violating decays $Λ_b\rightarrow Σ^0 ϕ$ and $Λ_b\rightarrow Σ^0 J/ψ$, proceed merely via the exchange topologies, in the framework of perturbative QCD approach. Assuming $Σ^0$ 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 a difficulty in observing them. We then extend our study to include the $Σ-Λ$ mixing.It is found that the mixing has significant effect on the $Λ_b\rightarrow Σ$ decays, especially it can greatly increase the rate of the $J/ψ$ 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.

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Zhou Rui, Jia-Ming Li, Chao-Qi Zhang. 2023-08-25. Estimates of the isospin-violating $Λ_b\rightarrow Σ^0 ϕ, Σ^0 J/ψ$ decays and the $Σ-Λ$ mixing. https://doi.org/10.1103/physrevd.108.033004

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