Measurements of CP violation in mixing of Bs mesons and the Ds production asymmetry at LHCb

  • Suzanne Klaver

Student thesis: Phd


This thesis reports two measurements performed using proton-proton collision data collected by the LHCb detector in 2011 and 2012, corresponding to an integrated luminosity of 3 inverse femtobarn and centre-of-mass energies of 7 and 8 TeV respectively. The first measures the CP asymmetry in Bs-anti-Bs oscillations, called asls. This is measured in inclusive Bs and anti-Bs to Ds mu nu X decays, where the Ds meson is reconstructed in the final state K K pi. The measurement is performed in three regions in the Dalitz phase space of the Ds decay, and corrected for detection and background asymmetries. A value of asls = (0.39 +/- 0.26(stat) +/- 0.20(syst))% is found, which is the world's most precise measurement of a CP asymmetry in B meson mixing and is consistent with the Standard Model prediction. The second measurement determines the production asymmetry of Ds mesons, and probes non-perturbative QCD models. It is performed in bins of transverse momentum and pseudorapidity in the kinematic region 2.5
Date of Award1 Aug 2018
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorChristopher Parkes (Supervisor) & Marco Gersabeck (Supervisor)


  • Ds meson
  • adhesives
  • data analysis
  • Bs meson
  • particle physics
  • production asymmetry
  • CP violation
  • LHCb
  • detection asymmetry

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