Observation of the decay $\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p\ddot{I}{€}^{-}$

Abstract

The Cabibbo-suppressed decay $\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p\ddot{I}{€}^{-}$ is observed for the first time using data from proton-proton collisions corresponding to an integrated luminosity of 6fb${}^{-1}$, collected with the LHCb detector at a centre-of-mass energy of 13TeV. Evidence for the $\hat{I}{›}_b^0\to \ddot{I}{‡}_{c2}p\ddot{I}{€}^{-}$ decay is also found. Using the $\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p{K}^{-}$ decay as normalisation channel, the ratios of branching fractions are measured to be $$\begin{array}{rclcccc}\frac{\mathcal{B}(\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p\ddot{I}{€}^{-})}{\mathcal{B}(\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p{K}^{-})}& =& (6.59\pm 1.01\pm 0.22)\times 10^{-2},\frac{\mathcal{B}(\hat{I}{›}_b^0\to \ddot{I}{‡}_{c2}p\ddot{I}{€}^{-})}{\mathcal{B}(\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p\ddot{I}{€}^{-})}& =& 0.95\pm 0.30\pm 0.04\pm 0.04,\frac{\mathcal{B}(\hat{I}{›}_b^0\to \ddot{I}{‡}_{c2}p{K}^{-})}{\mathcal{B}(\hat{I}{›}_b^0\to \ddot{I}{‡}_{c1}p{K}^{-})}& =& 1.06\pm 0.05\pm 0.04\pm 0.04,\end{array}$$ where the first uncertainty is statistical, the second is systematic and the third is due to the uncertainties in the branching fractions of $\ddot{I}{‡}_{c1,2}\to J/\ddot{I}ˆ{\hat{I}}^3$ decays.

19 pages, 3 figures, All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2021-003.html (LHCb public pages)". arXiv admin note: text overlap with arXiv:1806.08084