Angular Analysis of Bs->Phiee Decays and Implementation of Automated Analyses to Ensure Data Quality for Run3 of the LHCb Experiment

Overview & Synopsis

One of the effective ways to search for signs of New Physics (NP) beyond the Standard Model (SM) is through the study of b→sℓ+ℓ− (ℓ is a lepton) transitions, which involve Flavour Changing Neutral Currents (FCNC) via box or loop diagrams. While the SM predicts that the photon is predominantly left-handed in b→sγ transitions, with a small right-handed component, the presence of New Physics (NP) could manifest as a more substantial right-handed current. LHCb has previously conducted an angular analysis on B→K*ee in the low dielectron mass region where the primary contributions to the loop processes arise from the coupling of a virtual photon to the dielectron pair. It has delivered the world's most accurate measurement of photon polarization in b→sγ transitions. The objective of my thesis is to conduct an angular analysis on the Bs​→ϕe+e− decay channel in the low dielectron mass region, utilizing the complete LHCb dataset corresponding to an integrated luminosity of 9 fb-1 of proton-proton collisions. This analysis aims to provide a clean and novel measurement of photon polarization, marking the first instance of such an analysis with the Bs meson. Furthermore, it complements the previously established measurements in the B0 channel.The second aspect of my thesis involved the development of an online monitoring tool for use during Run 3 at LHCb. With the LHC transitioning to higher luminosity and generating larger data samples, real-time monitoring of physics variables becomes increasingly crucial. This automatic analysis tool is utilized to detect anomalies by conducting checks on data collected in real-time, ensuring the integrity and reliability of the experimental data.