Measurement of $\itΛ_\it{b}^0$, $\itΛ_\it{c}^+$ and $\hat{I}›$ decay parameters using $\itΛ_\it{b}^0 \to \itΛ_\it{c}^+ h^-$ decays

Abstract

A comprehensive study of the angular distributions in the bottom-baryon decays $\hat{I}{›}_b^0\to \hat{I}{›}_c^{+}{h}^{-}(h=\ddot{I}€,K)$, followed by $\hat{I}{›}_c^{+}\to \hat{I}›h^{+}$ with $\hat{I}›\to p\ddot{I}{€}^{-}$ or $\hat{I}{›}_c^{+}\to p{K}_{\mathrm{S}}^0$ decays, is performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$ collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 $\mathrm{Te}\mathrm{V}$. The decay parameters and the associated charge-parity ($CP$) asymmetries are measured, with no significant $CP$ violation observed. For the first time, the $\hat{I}{›}_b^0\to \hat{I}{›}_c^{+}{h}^{-}$ decay parameters are measured. The most precise measurements of the decay parameters $\hat{I}\pm ,{\hat{I}}^2$ and ${\hat{I}}^3$ are obtained for $\hat{I}{›}_c^{+}$ decays and an independent measurement of the decay parameters for the strange-baryon $\hat{I}›$ decay is provided. The results deepen our understanding of weak decay dynamics in baryon decays.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lbfence.cern.ch/alcm/public/analysis/full-details/3240 (LHCb public pages)