Study of radiative decays at LHCb and search for the Λb0->pπ-γ decay
[eng] The main goal of this thesis is to study the radiative decays produced in one of the four big detectors of LHC, LHCb, which focuses on the study of matter-antimatter asymmetry through b and c quarks. In particular, the Λb0->pπ-γ process is studied from the data collected during the Run 1 of...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/185674 |
| Acceso en línea: | https://hdl.handle.net/2445/185674 http://hdl.handle.net/10803/674266 |
| Access Level: | acceso abierto |
| Palabra clave: | Física de partícules Teoria quàntica de camps Particle physics Quantum field theory |
| Sumario: | [eng] The main goal of this thesis is to study the radiative decays produced in one of the four big detectors of LHC, LHCb, which focuses on the study of matter-antimatter asymmetry through b and c quarks. In particular, the Λb0->pπ-γ process is studied from the data collected during the Run 1 of LHC in 2011 and 2012. In order to reduce the systematic uncertainties, a similar process, Λb0->pK-γ is used as a normalisation mode. This mode shares the same kinematics as our signal, with the difference that is less suppressed by the Cabibbo-Kobayashi-Maskawa matrix as it involves an b->sγ flavour changing neutral current instead of a b->dγ. In parallel, an inclusive radiative trigger selection has been developed to be used starting in the Run 3 of LHC in 2022. This inclusive selection will allow to save a wide variety of radiative decays while adapting to the new data writing scheme, where only the signal candidate will be saved, in opposition to the Run 1 and 2 setups where the whole event is saved. These radiative processes are of great interest as they are sensitive to interactions or particles beyond the Standard Model of Particle Physics, and so they serve as strong tests. Up to this date, the results from particle physics experiments have confirmed the Standard Model predictions, despite there are some phenomena which have not been able to be included in it yet. These phenomena include the matter-antimatter asymmetry observed in the universe, dark matter or dark energy. From the theorical point of view, for example, the Standard Model does not include a quantum field theory description of general relativity, while it does for the strong and electroweak interactions. It is for this reason that the measurement of radiative decays is also useful in determining the validity of the different theoretical models developed to explain part of these phenomena. |
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