Pinning down |Δ c |=|Δ u |=1 couplings with rare charm baryon decays
Abstract
We study the full angular distribution of semileptonic rare charm baryon decays in which the secondary baryon undergoes weak decay with sizable polarization parameter, Ξc+→Σ+(→p π0) ℓ+ℓ- , Ξc0→Λ0(→p π-) ℓ+ℓ- and Ωc0→Ξ0(→Λ0π0) ℓ+ℓ- . Such self-analyzing decay chains allow for seven additional observables compared to three-body decays such as Λc→p ℓ+ℓ- , with different sensitivities to the |Δ c |=|Δ u |=1 weak couplings. Opportunities to test the standard model in c →u transitions with standard model null tests and other angular observables are worked out. We show that a joint model-independent analysis of the leptonic AFBℓ, hadronic AFBH, and combined forward-backward asymmetry AFBℓ H together with the fraction of longitudinally produced leptons, FL, is able to pin down the dipole couplings C7,C7' and the semileptonic (axial-) vector ones C10,C9',C10' . AFBH is also accessible with dineutrino c →u ν ν ¯ modes and probes right-handed currents.
- Publication:
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European Physical Journal C
- Pub Date:
- April 2022
- DOI:
- 10.1140/epjc/s10052-022-10302-3
- arXiv:
- arXiv:2202.02331
- Bibcode:
- 2022EPJC...82..357G
- Keywords:
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- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment
- E-Print:
- 24 pages, 3 figures, 2 tables