A measurement of charm mixing using D0->K±π∓π±π∓ decays at LHCb and the performance of a TORCH prototype

Thesis

A measurement of the charm-mixing parameters is made using promptly produced D⁰ →K^±π^∓π^±π^∓ decays, exploiting proton-proton collision data collected by LHCb during 2015–18 and corresponding to an integrated luminosity of 5.9 fb⁻¹ . The effective mixing parameters are interpreted in terms of the hadronic parameters of the D⁰ decay, which are valuable for studies of CP violation. This is the first measurement of D^∗ →D⁰π, D⁰ →K^±π^∓π^±π^∓ decays in bins of phase-space at a hadron collider.

A prototype Time Of internally Reflected CHerenkov light (TORCH) detector, designed to identify pions, kaons and protons in the momentum range 2–20 GeV/c, is employed in beam tests at the CERN PS. Measurements of the collected photon yields and single-photon time resolutions are performed for different particle entry points on the plate and compared to expectations. These studies show that the performance of the TORCH prototype approaches the design goals for the full-scale detector.

Authors: Smallwood, JC

• DOI: 10.5287/ora-xrd8d6rnn
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English