Dr. Lily Asquith (Argonne)
Isolated prompt photons provide a direct probe of short-distance physics, complementary to that provided by measurements of jets or vector-bosons. The data are sensitive to the gluon density of the proton. The inclusive prompt photon cross sections have been measured over a wide range of transverse momenta; the diphoton cross section has also been measured as a function of diphoton mass, total transverse momentum and azimuthal separation. The cross section for photons produced in association with jets is also measured as a function of various kinematic variables describing the photon+jet system. The results are compared to the predictions of next-to-leading-order QCD.
Collaboration ATLAS (CERN)