Search for new physics in multijet events with at least one photon and large missing transverse momentum in proton-proton collisions at 13 TeV

A search for new physics in final states consisting of at least one photon, jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of $13~\mathrm{TeV}$. The data correspond to an integrated luminosity of $137~\mathrm{fb}^{-1}$, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events with signal-like characteristics are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying $\mathrm{W}$, $\mathrm{Z}$, or $\mathrm{H}$ bosons. The observed data are found to be consistent with the expectation from standard model processes. The results are interpreted in the context of pair production of supersymmetric particles via strong and electroweak interactions, assuming simplified models. Depending on the details of the signal models, gluinos and squarks of masses up to $2.35$ and $1.43~\mathrm{TeV}$, respectively, and electroweakinos of masses up to $1.3~\mathrm{TeV}$ are excluded at $95\%$ confidence level.