The Preshower detector is part of the CMS endcap electromagnetic calorimeter, located in front of the lead tungstate crystals. It comprises two orthogonal planes of silicon strip sensors each preceded by a thin layer of lead. The purpose of the Preshower is to identify two closely spaced photons from π0 decays, allowing a reduction of one of the backgrounds to the two-photon decay channel of the intermediate mass Higgs boson - π0s in jets faking photons. Following a brief overview of the design of the Preshower, we present occupancy measurements and first in-situ absolute calibration.
|Journal||Proceedings of Science|
|State||Published - 2010|
|Event||35th International Conference of High Energy Physics, ICHEP 2010 - Paris, France|
Duration: 22 Jul 2010 → 28 Jul 2010