High Energy Physics Seminar

In the Standard Model of particle physics the three charged leptons - electron, muon and tau - have identical couplings when participating in electroweak interactions. This is the essence of a universal principle, known as lepton flavour universality, which has been confirmed by several measurements on a wide range of particle decays. Recently, several indications of possible deviations from this principle have been reported by different experiments puzzling the scientific community. New physics beyond the Standard Model can manifest itself via lepton-flavour-violating (LFUV) processes in collisions at the Large Hadron Collider (LHC). In this talk, I will discuss the LFUV physics program of the Compact Muon Solenoid (CMS) experiment at the LHC, focusing on the first measurement between taus and muons using Bc mesons.

After the conclusion of the LHC physics program in 2029, the machine will be upgrade to bring the instantaneous luminosity up to 7.5x10^-34 cm-2 s-1 at the High-Luminosity LHC. In order to perform this precision LFUV physics program also at this machine, outstanding tracking performance are needed. The current CMS tracker won't be able to cope with increased radiation levels and a maximum of 200 interactions per 25 ns beam crossing. The tracker will be replaced to provide relevant tracking information for each bunch crossing. 

In this talk, I will present the current research and development activities for the upgrade of the CMS outer tracker, with a focus on the its PS modules, made of one strip and one macro-pixel sensor. 

The talk is in 469 Lauritsen.

Contact theoryinfo@caltech.edu for Zoom link.