Measurement of the CKM angle in B-->D*K decays

Lead Research Organisation: University of Oxford
Department Name: Oxford Physics

Abstract

The CKM angle gamma remains one of the most interesting parameters in flavour physics. It can be accessed through a wide variety of B ->DX style decays. This project will study the decay chain B->D*h, D->Kshh where in each case h represents either a pion or a kaon.
The D->Kshh method involves the study of the distribution of the decay over the the Dalitz plot, and through combination of model-independent information from BESIII allows for a standalone measurement of the angle gamma. This is expected to be of good precision, but the full power of this measurement will be realised in the combination with other D decay modes which can suffer from multiple solutions.
In this project both decays of the D* will be considered and use is made of the 180 degree strong phase between them. The pion and photon will not be reconstructed. This results in a more complicated invariant-mass distribution, but at a significant gain of efficiency.

No measurements from this decay mode using this potentially powerful partial reconstruction technique have been performed. The challenges faced by this project will include care parameterisation of many similar background decays and optimising the working point and an investigation into the fit procedure where an iterative approach may be useful. The results are expected to be high impact.

The project will also encompass a measurement of gamma in B->Dh decays using data from LHCb Run3. This will require considerable effort in understanding the quality and behaviour of the data from this new detector. Particular focus will be given to the PID calibration which will impact all other early measurements from LHCb where the calibration channel studied (D*->D0pi) will be used to provide calibration data for all measurements.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/V506953/1 01/10/2020 30/09/2024
2422367 Studentship ST/V506953/1 01/10/2020 31/03/2024 Seophine Stanislaus