Study of WW Central Exclusive Production in the semileptonic channel with tagged protons at CMS detector

One of the most efficient approaches to look for physics Beyond the Standard Model is the use of the Effective Field Theory (EFT) to describe higher energy theoretical models at lower energies, like that of the LHC. In this type of scenario, it is possible to have additional couplings to describe gauge bosons self-interactions, such as anomalous Triple and Quartic Gauge Couplings (aQGCs). These anomalous gauge couplings can appear, for example, as an excess in the cross section of the γγ → WW process. The CMS subdetector Precision Proton Spectrometer (PPS) consists of detector stations at around 200 m on both sides of the interaction point, allowing to detect protons that remained intact after losing a fraction of their energy in the interaction. PPS is an extremely important tool to investigate Central Exclusive Production (CEP) with high levels of pileup collisions. CEP processes are characterized by p + p → p∗ ⊕ X ⊕ p∗, where ⊕ represents rapidity gaps, X is the central final state (which could be WW, ZZ, di-jet, etc.) and p (p∗) are the protons in the initial (final) state. An analysis of the CEP of W boson pairs for CMS data recorded during 2016 is presented in this thesis, considering aQGCs in the EFT dimension-6 scenario. The semileptonc channel was chosen, which is characterized in the final state by the presence of a muon, missing transverse energy and a single large jet in the central CMS detector plus two scattered protons in PPS. The dataset analyzed has an integrated luminosity of about 10 fb−1 and no event is found after the event selection. The aQGC parameters αW0/Λ2 > 5.0 × 10−4 GeV−2 and αWC /Λ2 > 15.0 × 10−4 GeV−2, considering a form factor of 500 GeV, were excluded at 95% C.L.. Although these limits were already excluded in the previous analysis the study presented discuss a prospect for the entire Run II CMS dataset (about 100 fb−1).