Thesis title: Search for leptoquarks coupling to muons in lepton- quark collisions at LHC
This thesis presents a search for leptoquarks from lepton-induced production produced at LHC and collected by the CMS experiment.
Leptoquarks (LQs) are hypothetical particles foreseen by some extensions of the Standard Model (SM). These particles carry both lepton and baryon quantum numbers and therefore couple to both quarks and leptons. In particular, LQs can be produced from an interaction of a lepton and a quark. Searches for LQs have been performed in the past 20 years at various colliders (HERA, Tevatron and LHC).
The proposed project will extend the search for leptoquarks exploiting a novel production mechanism (in proton-proton collision at LHC). Due to quantum fluctuations, protons also contain charged leptons, making it possible to study lepton-induced processes. By picking a lepton from one beam and a quark from the other beam, it becomes possible to study the resonant single LQ production and the corresponding decay (l+q-->LQ-->l+q). The final state includes a lepton and a jet from the quark hadronization with high energy, allowing a cleaner experimental signature with respect to past searches. The main physical observable is the invariant mass of the lepton-jet system which distribution peaks to the LQ mass. This search will be more sensible than previous analyses for large LQ-lepton-quark coupling (>0.1) and for LQ masses (>1 TeV).