Search for Charged Lepton Flavor Violation (CLFV) in Compact Muon Solenoid (CMS) data
The lepton number conservation law is one of the most fundamental principles of the Standard Model. An example of breaking this rule for charged leptons (CLFV) would be the decay of the lepton into three muons: τ→μμμ. (or also μ→eeee). Processes of this type have been sought for many years and therefore it is known that, if they occur at all, they are very rare processes. Thus, large numbers of case studies are needed to discover them. The data collected by the CMS detector made it possible to set limits for the occurrence of the τ→μμμ process in a complex analysis [1]. After adopting some simplifications, a similar analysis can be carried out more simply as part of the proposed exercise. The content of the exercise is the analysis of the effective mass distribution of three muons from a set (ROOT file) containing three or more muons from about 100,000 pp interactions with a total energy of 13 TeV. There are also sets with the results of Monte-Carlo calculations. There is also a program available (C++) that reads the mentioned sets and creates a histogram of the transverse momentum of the muons.
Supervisor: prof. dr hab. Krzysztof Doroba (email: krzysztof.doroba@fuw.edu.pl)
[1] CMS Collaboration, Search for the lepton flavor violating decay τ → 3μ in proton-proton
collisions at sqrt(s)= 13 TeV, JHEP 01 (2021) 163, arXiv:2007.05658