Detection methods for long lived particles at the LHC
Almost all the extensions of the Standard Model predict the existence of new charged particles; these particles should be very heavy since they have excaped detection so far. In general, such heavy particles decay as soon as they are produced, but under certain circumstances they can be long-lived or even stable. There are two classes of models which predicts the existence of long-lived particles : models with a weakly broken symmetry, where the particle would be stable if the symmetry were exact; and models with an exact symmetry which forbids the decay of heavy exotics into ordinary particles, where the decay of the charged particle into a neutral particle is suppressed either by small couplings or by phase space. Examples of the second kind are supersymmetric models with exact R-parity, where the lightest supersymmetric particle is the gravitino. In this talk we will focus on GMSB (Gauge Mediated Supersymmetry Breaking) which belongs to this kind of models. In GMSB supersymmetry is broken in a so called hidden sector at a scale \( \sqrt F \) and transmitted to SM particles via a messenger sector. The transmission of the supersymmetry breaking is mediated by gauge fields, in particular by N singlet representations of SU(5).
KeywordsSupersymmetry Breaking SUSY Breaking Hide Sector Gravitino Mass Electromagnetic Calorimeter
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