Search for the doubly heavy Ξbc0 baryon via decays to D0pK−

Abstract

A search for the doubly heavy Ξbc0$$ {\Xi}{bc}^0 $$ baryon using its decay to the D0pK– final state is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is found in the invariant mass range from 6.7 to 7.2 GeV/c2. Upper limits are set at 95% credibility level on the ratio of the Ξbc0$$ {\Xi}{bc}^0 $$ production cross-section times its branching fraction to D0pK− relative to that of the Λb0→D0pK−$$ {\Lambda}b^0\to {D}^0{pK}^{-} $$ decay. The limits are set as a function of the Ξbc0$$ {\Xi}{bc}^0 $$ mass and lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and in the transverse momentum region from 5 to 25 GeV/c. Upper limits range from 1.7 × 10−2 to 3.0 × 10−1 for the considered Ξbc0$$ {\Xi}_{bc}^0 $$ mass and lifetime hypotheses.