Physics:Preshower detector

Preshower detector is a thin detector installed on the front of electromagnetic calorimeters with the goal of counting charged particle originating from interaction of primary particles produced in particle accelerators with inactive material. It can be used to separate hadrons from electrons and photons and to localize electromagnetic showers. It is also used for correction of energies of primary-produced leptons and hadronic jets . Such detectors were installed for the ZEUS, CDF, ATLAS, STAR, CMS and LHCb experiments.

.

Preshower detectors can use different technologies. The ZEUS experiments uses plastic-scintillator pads. In the CMS detector, the two crystal endcap calorimeters were supplemented with a preshower detector. The purpose of this detector was to distinguish neutral pions from photons. This is motivated by the need to minimize the background from neutral pions in the search for the Higgs bosons in the two-photon decay.