Depth-dependent Clustering of Hadronic Showers at the LHC

Abstract

The hunt at the Large Hadron Collider (LHC) for new physics beyond the Stan dard Model pushes the collider’s current limits. Searching for new physics implies a need for high luminosity, which poses immense challenges for the collider detec tors that will have to record the information for approximately 200 proton-proton collisions in 25 nanosecond intervals. At the Compact Muon Solenoid (CMS), one of the four major experiments at the LHC, the hadron calorimeter (HCAL) is undergoing significant hardware upgrades in order to facilitate the search for new physics. The current method used to separate and measure the energy of hadronic showers (from pions, for example) degrades rapidly as the probability for the spa tial overlap of pion showers grows with increasing luminosity. Accessing segments of the detector in three-dimensions with depth-dependent clustering would allow us to leverage low occupancy region of the hadron calorimeter to improve the separation of hadronic showers. Reconstructing these showers more accurately will help us better identify the hadronic particles coming from elementary particle interactions produced in LHC collisions and ultimately to better understand ele mentary particle physics and perhaps address questions that are still unanswered by the Standard Model.