High Energy Physics Seminars

Electron and photon reconstruction in CMS: Some studies

by Dr. Shilpi Jain (Univ. of Minnesota, USA)

Monday, October 25, 2021 from to (Asia/Kolkata)
Undeniably, the electrons and the photons play crucial roles in a wide range of analyses at the LHC, including precision physics and searches for physics beyond the Standard Model. The final states of 2 photons and 4 leptons were two of the search channels which saw the first signs of the Higgs boson during Run 1 of the LHC. In this talk, I will give an overview of the reconstruction and identification of electrons and photons in the electromagnetic calorimeter of the CMS experiment, their performance in Run 2 and the improvements planned for Run 3. During the high-luminosity era of the LHC, the endcap calorimeter will be replaced by the High Granularity Calorimeter.  There have been test beam activities at CERN during 2016-2018 to test a prototype of this detector. I will discuss how the shower shape properties of the same electrons and photons can change in such a sampling calorimeter. Photons detected in an event can come from non-collision sources and can be a huge background to various searches. We have beam halo monitors to detect such a background. I will discuss their working principle and the plans for Run 3.