Abstract
A first search for the $ \varXi_{bc}^+ \to J/\psi \varXi_c^+ $ decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb−1 recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local (global) significance of $ 4.3\,(2.8) $ and $ 4.1\,(2.4) $ standard deviations at masses of 6571 and 6694 MeV/$c^2$, respectively. Upper limits are set on the $\varXi_{bc}^+$ baryon production cross-section times the branching fraction relative to that of the $B_{c}^{+} \rightarrow J / \psi D_{s}^{+}$ decay at centre-of-mass energies of 8 and 13 TeV, in the $ \varXi_{bc}^+ $ and in the $ B_{c}^{+} $ rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to $ 20\;{\rm{GeV}} /{c} $, respectively. Upper limits are presented as a function of the $ \varXi_{bc}^+ $ mass and lifetime.
LHCb Collaboration