2010/10/05 by Sanjoy Biswas, Joydeep Chakrabortty, Sourov Roy
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1103/physrevd.83.075009
published as Phys.Rev.D83:075009,2011 · 10 pages; 6 figures
arxiv created 2010/10/05 · openalex publication_date 2011/04/12 · arxiv updated 2015/03/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study a distinct supersymmetric signal of multiphotons in association with jets and missing transverse energy. At least one of these photons has the origin in displaced vertex, and thus it is delayed and nonpointing. We consider a supersymmetric scenario in which the gravitino is the lightest supersymmetric particle (LSP) (with a mass \ensuremath∼1 keV) and the lightest neutralino is the next-to-lightest supersymmetric particle (NLSP). The NLSP decays dominantly into a photon and a gravitino within the detector with a decay length ranging from c\ensuremathτ_\stackrel\texttildelow\ensuremathχ\ensuremath∼50--100 cm. In addition, we assume that the second-lightest neutralino and the lightest neutralino are nearly degenerate and this leads to a prompt radiative decay of the next-to-lightest neutralino into a photon and a lightest neutralino with a large branching ratio. Such degenerate neutralinos can be realized in various representations of the SU(5), SO(10) and E(6) GUT group. The nonpointing photons can be reconstructed at the electromagnetic calorimeter of the ATLAS detector, which have been designed with good timing and directional resolution. We find that with a center-of-mass energy Ecm=14 TeV at an integrated luminosity of 100 fb^\ensuremath-1 one may see evidence of hundreds of triphoton events at the LHC, in addition to several thousands diphoton events. We also predict the event rates even at the early phase of LHC run.