Rare hadronic decays of charged B mesons at LHCb

Thesis

This thesis documents two searches for rare hadronic decays of B⁺ mesons with the LHCb experiment at the Large Hadron Collider. Both are performed using proton-proton collision data corresponding to an integrated luminosity of 4.8 fb⁻¹, collected at centre-of-mass energies of 7, 8 and 13 TeV during 2011–2016.

The first is a search for B⁺ → D_s⁺K⁺K⁻ decays. A significant signal is observed for the first time and the branching fraction is determined to be B(B⁺ → D_s⁺K⁺K⁻) = (7.1 ± 0.5 ± 0.6 ± 0.7) × 10⁻⁶, where the first uncertainty is statistical, the second systematic and the third due to the uncertainty on the branching fraction of the normalisation mode B⁺ → Ds⁺D⁰.

The second search is performed for the rare pure annihilation decay B⁺ → D_s⁺φ. No significant signal is observed and a limit of B(B⁺ → D_s⁺φ) < 4.9 × 10⁻⁷ is set on the branching fraction at 95% confidence level.

Authors: Hadavizadeh, T

• DOI: 10.5287/ora-g7nkbdjzz
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: Particle Physics; Physics; LHCb; Flavour Physics
• Subjects: Particle Physics