Version 8.1 by Ricardo Julio Rodríguez Fernández on 2025/09/01 14:00

Hide last authors
Ricardo Julio Rodríguez Fernández 6.1 1 === Machine Learning Tools for Precision Tests of the Standard Model at LHCb ===
2 ==== Supervisor: Julio Novoa Fernández
Ricardo Julio Rodríguez Fernández 2.1 3 ====
4
Ricardo Julio Rodríguez Fernández 6.1 5 Leptons are a fundamental class in the Standard Model (SM) of particle physics. According to this model, there is no apparent difference between leptons apart from their masses - this is known as Lepton Flavour Universality (LFU). However, recent measurements of LFU observables show significant disagreement with respect to SM predictions, which could suggest new physics
6 beyond SM.
Ricardo Julio Rodríguez Fernández 3.1 7
Ricardo Julio Rodríguez Fernández 6.1 8 To reduce their uncertainty and solve the current situation, these LFU observables need to be measured with great precision. In particular, the experimental data has to be carefully processed to separate “signal” and “background” events. This selection includes Machine Learning (ML) tools that improve the efficiency of this procedure.
9
10 This project will introduce the student to the use of ML in high-energy physics. In particular, the
11 student will:
12
13 * Analyse real data from LHCb, one of the main experiments of the Large Hadron Collider at CERN (the world’s largest and most powerful particle accelerator).
14 * Learn how ML is used for measuring LFU observables with better accuracy, by implementing tools such as neural networks, decision trees and more.
15 * Train and optimise their own ML models with different Python environments, which they could apply to other physical phenomena and beyond.
Ricardo Julio Rodríguez Fernández 7.1 16
17 ----
18
19 === P1 - ML study for B->D* 3Pi decays ===
Ricardo Julio Rodríguez Fernández 8.1 20 ==== Summer Fellow: Guillermo Fuentes Morales
21 ====
Ricardo Julio Rodríguez Fernández 7.1 22
23 This decay is used as the normalization channel for the semileptonic ratio R(D*), one of the LFU observables that is studied at LHCb. In this particular case, the D* meson decays into a pion and a D meson, which then decays into a kaon and three pions.
24
25 ----
26
27 === P2 - ML study for B->D 3Pi decays ===
Ricardo Julio Rodríguez Fernández 8.1 28 ==== Summer Fellow: Guillermo Fuentes Morales
29 ====
Ricardo Julio Rodríguez Fernández 7.1 30
31 A related LFU observable is the semileptonic ratio of branching fractions R(D). One possible choice for the normalization channel is B->D 3Pi, where D decays into two pions and a kaon.
32