Finding true LUV

Lead Research Organisation: University of Glasgow
Department Name: School of Physics and Astronomy

Abstract

Over the last few decades, the Standard Model (SM) of particle physics, which describes our current knowledge of nature at fundamental scales, has been probed by a broad variety of experiments, and it has successfully predicted, and/or explained most of the physical phenomena observed so far. A notable verification of the power of the SM was the discovery in 2012 of its final piece, the Higgs boson. However, as Isaac Asmiov famously said, "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'that's funny!'", and luckily there are still "funny" phenomena, which are not completely understood in our theoretical description, and are the subjects of today's searches for new particles and forces. In our current understanding, matter consists of twelve fundamental particles: the six quarks (u, d, s, c, b, t ordered by increasing mass), and six leptons, including the electron with its heavier partners, the muon and the tau, and their three associated neutrinos.
Just as the neutrinos have surprised us in the last decades, the charged leptons (electron, muon, tau) are also important to investigate. We expect the charged leptons to have identical properties, besides their mass, and to be produced with the same probability by the same processes (Lepton Universality). Instead, the most recent experimental results hint at a breaking of this principle (Lepton Universality Violation - LUV). The goal of my proposal is to shed some light on these anomalies: to confirm or disprove the effect and investigate which type of processes beyond our current theoretical description are responsible for such "funny" observations.
The most precise tests of lepton universality compare b-hadrons, bound states of quarks, containing at least a quark (or antiquark) of b-type decaying into particles including different charged leptons and neutrinos. I will measure the difference in the abundance of these decays in nature with high precision, in order to establish if lepton universality is violated or not. In addition, I will measure different quantities to better understand the processes responsible for these b-hadrons decays, identifying the nature of possible new physics phenomena.
I will use samples of millions of b-hadron decays collected with the LHCb experiment at the Large Hadron Collider (LHC). The LHC, located 100m underground just outside Geneva, collides protons at energies that have never previously been reached in a laboratory on Earth and the LHCb experiment is currently the best apparatus to measure b-hadron properties. To ensure ultimate precision in these measurements, I will propose a tracking system design for future LHCb upgrades during the High-Luminosity LHC phase (2026-2038).
I will face several significant challenges, including the exploration of new strategies to analyse huge data samples, development of efficient software using the latest computing technologies, and design of new detectors using emerging technologies. By addressing these challenges, my proposal generates an impact in science and industry beyond the immediate scientific scope of the project.

Publications

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Description HFLAV 
Organisation Heavy Flavor Averaging Group
Sector Public 
PI Contribution I joined the semileptonic group in HFLAV as a representative from the LHCb experiment. My duties include updating of the software tools used to provide the combination of available experimental results as well as providing combined results in the relevant area.
Collaborator Contribution HFLAV periodically updates combinations of flavour physics experimental results. Every two years these results are presented in a publication. Preliminary combinations are provided more frequently for highly anticipated measurements.
Impact Working towards the bi-yearly update, publication process is expected to start at the end of 2023
Start Year 2023
 
Description CERN Courier article about future LHCb upgrades 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact The CERN Courier report on international high-energy physics and, in addition to CERN, most of the particle physics groups in the universities and labs have a subscription to the magazine. An online version is openly available to everyone, making the articles/features accessible to researches, undergraduate and postgraduate students and to the general public. I am one of three co-authors of an article showcasing the future upgrade of the LHCb experiment, the flavour physics experiment at the LHC. This experiment is designed to achieve the ultimate precision in the flavour physics observables studied until now and to be studied in the future. In an historical moment when the future of experimental particle physics is more often than not under discussion, showing the plans to upgrade our experiment, prospects for new measurements and the on-going research and development to achieve these goals is essential to include the scientific community, students who might dedicate their projects and future research, the decision makers and the public opinion.
Year(s) Of Engagement Activity 2022,2023
URL https://cerncourier.com/a/lhcb-looks-forward-to-the-2030s/
 
Description IOP Winter Lecture at the Royal Society of Edinburgh 'Where is the LUV? Indirect searches for new particles/interactions at LHCb' 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Other audiences
Results and Impact This public lecture was given as part of the yearly IOP Winter Lectures at the Royal Society of Edinburgh. These lectures attract a broad audience, including students from last years of high school, undergraduate and postgraduate students, fellow researches, retired scientists, general public interested in science. Lepton universality is a central principle of the Standard Model of particle physics, recent experimental results highlighted a tension between measurements and predictions, suggesting a promising route to find and characterise new particles and interactions. Sharing the most recent results and possible giving a glimpse of the implications of on-going measurements shows our colleagues of other fields and our society one area of the forefront of fundamental physics research.
Year(s) Of Engagement Activity 2023
URL https://www.iop.org/events/where-luv-indirect-searches-new-particlesinteractions-lhcb