A search for the Higgs boson decay to two electrons with the Compact Muon Solenoid experiment

A search is presented for the Higgs boson decay to a pair of electrons in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data set was collected with the Compact Muon Solenoid experiment at the Large Hadron Collider between 2016 and 2018, corresponding to an integrated luminosity of 138 fb^{−1}. The analysis develops event categories targeting Higgs boson production via gluon fusion and vector boson fusion, defined by selection on dedicated machine learning-based classifiers. An upper limit on the Higgs boson branching fraction to an electron pair is determined as 3.0x10^{−4} at the 95% confidence level, which is the most sensitive limit to date.