Project description
Boosting the physics reach of LHCb using machine learning
LHCb is a particle physics experiment specialising in the properties and decays of heavy particles containing beauty and charm quarks created in proton–proton collisions at the LHC. In Run 3, LHCb will collect physics events at higher rates thanks to newly installed detectors and a revolutionary software trigger that will enable LHCb to rapidly process signal data. The EU-funded LHCbDFEI project will design full event interpretation algorithms to enhance the trigger performance. A deep neural network will process the low-level information from the detector and infer the heavy-hadron decays that occurred in the event, allowing quick identification of different types of background events and providing further information on parent particles. As a first application of DFEI, a new analysis of the quantum amplitudes of beauty-hadron decays with a tau lepton will be performed, with important consequences for tests of the Standard Model of particle physics.
Objective
The LHCb experiment has shown an excellent performance in precision measurements of beauty- and charm-hadron decays during the LHC runs 1 and 2. Now, it is undertaking its first major upgrade, to face the challenges of a large increase in instantaneous luminosity, that implies augmented event complexity and background levels. This impacts the trigger, which needs to quickly and efficiently identify signals, while facing limits on the disk storage capacity. The proposed project aims at fighting these limitations in a new way for LHCb: performing a Deep Full Event Interpretation (DFEI) during trigger, where a deep neural network processes the low-level information from the detector and infers the heavy-hadron decays that occurred in the event. This allows to quickly identify different types of background and provides enhanced information on the mother particles. As a first application of DFEI, the first angular analysis of semitauonic decays at LHCb is proposed. Semitauonic decays are partially reconstructed in LHCb, due to the presence of neutrinos in the final state. This leads to high levels of backgrounds, hard to separate from the signal, which makes them a perfect validation bench for the power of DFEI. From a physics perspective, the recently-observed flavour anomalies defy the concept of Lepton Universality of the Standard Model (SM), and point towards potential beyond-the-SM effects in semitauonic B decays. The complementary aim of this project is to perform the first LHCb angular analysis of both B0 -> D+ tau- nu and B0 -> D*+ tau- nu decays, where D*+ -> D+ pi0 and tau- -> mu- nu nu. This analysis will provide crucial information to discriminate between different new models proposed to explain the anomalies. The ambitious projects in this proposal are solidly based on my experience with semitauonic decays, angular analyses and the creation of new software tools, as well as the broad experience of the host group in event reconstruction and data analysis.
Fields of science
- natural sciencescomputer and information sciencesdata science
- natural sciencesphysical sciencestheoretical physicsparticle physicsneutrinos
- natural sciencescomputer and information sciencessoftware
- natural sciencesphysical sciencestheoretical physicsparticle physicsleptons
- natural sciencescomputer and information sciencesartificial intelligencecomputational intelligence
Keywords
Programme(s)
Funding Scheme
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinator
20126 MILANO
Italy