Search for the Doubly Charmed Baryon Ξ+cc in Ξ+cc → pD+K−

A preliminary search for the doubly charmed baryon Ξ+cc is performed via the decay channel Ξ+cc → pD+K−, where the long lifetime of D+ can be helpful to improve the sensitivity in search of Ξ+cc. A detailed study on trigger cuts efficiency in Turbo has been carried out and a dedicated Particle identification (PID) correction has been implemented in calibration of Monte-Carlo samples to match the data. The removal of cloned and duplicated candidate events is also applied in the reconstruction procedure to reduce the background. In this study, the lifetime of Ξ+cc is reweighed to 45 fs according to latest theoretical prediction. To better separate signal events from background, the MVA technique is also used in the event-selection, where the best performance is given by BDTF classifier at 0.52 working point optimised by Punzi FoM. All selections and the optimal BDT cut have been applied in the blinded distribution of Ξ+cc, and no fake signal peak has been observed.