Currently, the most important mandate of the ATLAS and CMS experiments at the CERN-LHC is to characterize the Higgs boson precisely to establish if it is the scalar as envisaged in the standard model or if it belongs to some new physics scenario. The self-coupling properties of the Higgs boson are yet to be measured in data, though the trilinear coupling has already been constrained. In some scenarios beyond the standard model, trilinear self-coupling can be different from quartic coupling. At the LHC, the triple Higgs boson production provides direct access to the quartic coupling, though the process is extremely rare. This talk will present our ongoing search for the triple Higgs boson production in the gluon fusion mode and decay to the final state of four b jets and two photons.
At the ongoing LHC Run-3, the 2022 data are crucial in obtaining the calibrations for the electromagnetic calorimeter of the CMS experiment, which is required for the Level-1 trigger. The second part of the talk will cover our study on the performance of electrons/photons in Level1 trigger in 2022 and updates for the 2023 operations.