Search for the doubly heavy $\mathit{\Xi}_{bc}^{0}$ baryon via decays to $D^0pK^-$

TL;DR

This study searches for the doubly heavy Xi_bc^0 baryon decaying to D^0 p K^- using LHCb data but finds no evidence, setting upper limits on its production relative to Lambda_b^0 across various mass and lifetime hypotheses.

Contribution

First search for Xi_bc^0 baryon decaying to D^0 p K^- in proton-proton collisions at 13 TeV, establishing upper limits on its production rate.

Findings

No significant signal observed in the mass range 6.7 to 7.2 GeV/c^2.

Upper limits on production cross-section ratio range from 1.7×10^{-2} to 3.0×10^{-1}.

Limits vary with mass, lifetime, rapidity, and transverse momentum hypotheses.

Abstract

A search for the doubly heavy $\mathit{\Xi}_{bc}^{0}$ baryon using its decay to the $D^0pK^-$ 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 $\mathrm{fb}^{-1}$. No significant signal is found in the invariant mass range from 6.7 to 7.2 $\mathrm{GeV}/c^2$. Upper limits are set at $95\%$ credibility level on the ratio of the $\mathit{\Xi}_{bc}^{0}$ production cross-section times its branching fraction to $D^0pK^-$ relative to that of the $\mathit{\Lambda}_{b}^{0} \to D^0pK^-$ decay. The limits are set as a function of the $\mathit{\Xi}_{bc}^{0}$ mass and lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and in the transverse momentum region from 5 to 25 $\mathrm{GeV}/c$. Upper limits range from $1.7\times10^{-2}$ to $3.0\times10^{-1}$ for the considered $\mathit{\Xi}_{bc}^{0}$ mass and lifetime hypotheses.