This thesis describes two separate analyses that attempt to search for, and quantify, CP violation and mixing in the charm quark sector using samples of D0 mesons collected by the LHCb experiment during Run 2, from 2015â18. The first analysis uses an unbinned, model-independent approach (the energy test) designed to search for localized CP violation in the decay D0 â ÏâÏ+Ï0. With a total signal yield of approximately 2.3M, a p-value of 0.62 is observed under the null hypothesis of CP symmetry indicating no evidence of CP violation in the sample analysed. The second analysis describes work performed towards the measurement of CP violation and mixing in the doubly Cabibbo suppressed decay D0 â K+ÏâÏ+Ïâ. A signal yield of approximately 320,000 decays is observed. Studies of the back- ground component identify that it is dominated by mis-tagged D0 â KâÏ+ÏâÏ+ candidates. Several important inputs to the measurement are developed, includ- ing the amplitude model and mixing framework, the multidimensional acceptance model, and the characterisation of backgrounds. Initial validation and sensitivity studies are presented using realistic Monte Carlo (MC) pseudo-experiments. Work on updating LHCb alignment software is also documented. The nature of this work involves enabling the use of multi-threading during the alignment of the detector in preparation for Run 3 of the Large Hadron Collider.
Date of Award | 1 Aug 2023 |
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Original language | English |
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Awarding Institution | - The University of Manchester
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Supervisor | Christopher Parkes (Supervisor) & Marco Gersabeck (Supervisor) |
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Studies of CP violation and mixing in D0 decays
Cobbledick, J. (Author). 1 Aug 2023
Student thesis: Phd