Graviton-induced bremsstrahlung

Abstract

We discuss photon bremsstrahlung induced by virtual graviton exchange in proton-proton interactions at hadronic colliders, resulting from the exchange of Kaluza-Klein excitations of the graviton. The relevant subprocesses $g\stackrel{\ensuremath{\rightarrow}}{g}\stackrel{\ensuremath{\rightarrow}}{G}{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\gamma}$ and $q\overline{q}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\gamma}$ are discussed in both the Arkani-Hamed--Dimopoulos--Dvali and the Randall-Sundrum scenarios. Although two-body final states (or real graviton emission) would presumably be the main discovery channels, a search for three-body final states could be worthwhile since such events have characteristic features that could provide additional confirmation. In particular, the ${k}_{\ensuremath{\perp}}$ distribution of the photon is in both scenarios harder than that of the standard-model background.