A search is conducted for new physics in a final state containing a photon
and missing transverse momentum in proton-proton collisions at √
s = 13 TeV. The data
collected by the CMS experiment at the CERN LHC correspond to an integrated luminosity
of 12.9 fb−1
. No deviations are observed relative to the predictions of the standard model.
The results are interpreted as exclusion limits on the dark matter production cross sections
and parameters in models containing extra spatial dimensions. Improved limits are set with
respect to previous searches using the monophoton final state. In particular, the limits on
the extra dimension model parameters are the most stringent to date in this channel.