arXiv subjects
Publications and source records attributed to S. Ogilvy.
The performance of the ring-imaging Cherenkov detectors at the LHCb experiment is determined during the LHC Run 2 period between 2015 and 2018. The stability of the Cherenkov angle resolution and number of detected photons with time and running conditions is measured. The particle identification performance is evaluated with data and found to satisfy the requirements of the physics programme.
We report a search for the doubly charmed baryon $Ξ_{cc}^{+}$ through the decay $Ξ_{cc}^{+} \to Λ_{c}^{+} K^{-} π^{+}$, using a data sample corresponding to an integrated luminosity of $0.65~\mathrm{pb^{-1}}$ of $pp$ collisions at $\mathrm{\sqrt{s}} = 7~\mathrm{TeV}$. In the mass range 3300-3800$~\mathrm{MeV}/c^{2}$ no significant signal is observed. Upper limits at $95\%$ confidence level are set on $R$, the ratio of the production cross section of the $Ξ_{cc}^{+}$ times the relevant branching fraction over the $Λ_{c}^{+}$ cross section, as a function of the $Ξ_{cc}^{+}$ mass and lifetime. The largest upper limits on $R$ over the investigated mass range are $R<1.5\times10^{-2}$ for a lifetime of $100~\mathrm{fs}$ and $R<3.9\times10^{-4}$ for a lifetime of $400~\mathrm{fs}$.