Calibration of Electrons or Photons Reconstructed by the Level 1 Trigger of CMS for Run 3

The Level-1(L1) trigger is the first of the two-level trigger system of the CMS detector [2] and is hardware based. It gathers information from the Electromagnetic (ECAL) and Hadron (HCAL) Calorimeters and Muon detectors to select interesting physics events. The L1 Electron/Photon ( \(e/\gamma \) ) trigger identifies \(e/\gamma \) candidates based on energy deposition in the ECAL and HCAL. The present data taking period of LHC, the Run 3 has just started. We are going to present here the studies that were performed to prepare the L1 \(e/\gamma \) trigger for the Run 3 data taking. This includes analyzing and optimizing the efficiency and resolutions of L1 \(e/\gamma \) triggers at a feasible trigger rate. The optimisation focused on developing a new set of monte-carlo based calibrations and isolation schemes that puts a limit on the transverse energy around the candidate \(e/\gamma \) to maximise the physics reach of CMS. Resolutions of the L1 \(e/\gamma \) trigger in the recent Run 3 data will also be presented.