Angles and B-mons
The best model currently available to describe fundamental forces and building blocks of matter is the Standard Model (SM) of particle physics. According to the Standard Model, the Universe is composed of particles that make up matter — quarks and leptons — and particles that carry the interactions between them. One of the quarks, called a beauty quark b, is the focus of Aleksandra Snoch's dissertation.
Investigating the decays of the beauty quark can provide an insight into physics beyond the Standard Model. In particular, Snoch's research focuses on the b→sll transition. According to the Standard Model, this process is very rare, making it easier to observe potential contributions from new physics, even if they are small.
The decay of interest in this search is B→K*ee. The analysis is performed by fitting an angular function to the distributions of the decay angles and comparing the best-fit parameters with SM predictions. To ensure reliable results, the angular analysis is performed first using a ''control channel'': a decay that results in the same particles but is well known and agrees with the Standard Model predictions. In this analysis, the control decay is B→K*J/ψ(→ee). An angular analysis of this decay is the main topic of Snoch's thesis.