High Energy Physics Seminars

Photons as probes for new physics

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

Friday, October 22, 2021 from to (Asia/Kolkata)
Description
A large amount of direct evidence supports the presence of new physics beyond the standard model (SM) of particle physics. The fact that results from Run 2 (2015-2018) of the LHC are consistent with the SM, tells us that the new physics scale is either out of reach of the LHC or the couplings are too weak. By looking for new physics signatures in multiple ways, one can cover both the possibilities. Searches for rare decays of the Higgs boson (H) are important as these have not yet been observed.  The H --> ll𝛾 process, where l is e or μ, can be sensitive to indirect signs of new physics. It is important to build search strategies which are effective enough such that such rare decay modes do not go undetected. Instead, if the energy scale of new physics lies above the energy scale directly accessible at the LHC, its effects could be observed in the tails of the kinematic distributions of the final state objects. Similarly, in another possibility, like the presence of triple gauge boson anomalous couplings between the Z-bosons and photons, the distribution of photon transverse momentum at large values may be enhanced. In this talk, I will cover both these scenarios and search strategies which we developed for the CMS experiment during Run 2 data taking. I shall also present the recent improvements achieved for the mitigatation of the backgrounds for specific searches.