Search for a disappearing track signal at the CMS detector.
A search for long-lived charged particles (LLP) that produce a signature of a disappearing track within the CMS is presented. The search is based on minimal freeze-in models that explain the abundance of dark matter in the Universe. We propose that the long-lived charged particle, a particle Beyond Standard Model (BSM), decays into a lepton of the Standard Model (SM) and a Feebly Interacting Massive Particle (FIMP), an invisible particle (e.g Dark Matter). Candidate disappearing tracks are identified as isolated tracks that disappear in the outermost regions of the silicon tracker. For this study, a code was developed to simulate the pair production of the LLP in pp collision with a center-of-mass energy of 13 TeV. We explore the parameters of the models such as lifetime and particle mass of the LLP and FIMP. For simulation, we can tools like MadGraph, Delphes and Pythia 8. The idea is that the difference in mass between the LLP particle and the FIMP is small in the order of 1 GeV/c2 so that the generated lepton has such a small momentum that its track cannot be reconstructed. Therefore, our signal is basically Missing Energy Transverse, MET. To observe the signal, we study the PT produced by the recoil of LLP particles against Initial State Radiation (ISR). At the end, the estimated amounts of the signal are presented.