Finding true LUV

Lead Research Organisation: University of Manchester
Department Name: 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

10 25 50
 
Description Capital Equipment for Early Career Academic Staff grant
Amount £40,000 (GBP)
Organisation University of Glasgow 
Sector Academic/University
Country United Kingdom
Start 03/2022 
End 03/2024