An Angular Analysis of B→ K+e+e- Decays at the LHCb Experiment

  • Samuel Maddrell-Mander

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)


Recent anomalies in the b→sll sector point towards possible Lepton Flavour Universality (LFU) violating effects coupling to (axial-)vector currents.
An angular analysis of the differential decay rate of B+ → K+e+e- decays is used to measure the observables AFB and FH using data from pp collisions gathered at the LHCb experiment between 2011 and 2016. This dataset corresponds to a total integrated luminosity of 5fb-1.
The angular observables AFB and FH are only sensitive to (pseudo-)scalar and (pseudo-)tensor couplings for Standard Model (SM) like values of the observables, which therefore provides an avenue to check LFU effects and to validate the electron reconstruction at the LHCb experiment.
The decay distribution is fit using a binned likelihood method, and angular observables are presented as a likelihood surface using a two dimensional Feldman Cousins construct. The result of the likelihood fit is compatible with the Standard Model prediction within 1σ.
This angular analysis is the first of its kind.
Date of Award23 Mar 2021
Original languageEnglish
Awarding Institution
  • University of Bristol
SupervisorKonstantinos A. Petridis (Supervisor)

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