Looking forward to B_{c + →} τ+ ν_τ

Searching for new physics via B-meson decay

In recent years, several measurements have revealed small but persistent deviations from the predictions of the Standard Model. These studies compare how often a B meson, a particle containing a bottom quark, decays into a tau lepton versus a lighter lepton, such as an electron or a muon. The Standard Model predicts equal rates once mass differences are accounted for, but results show a slight excess of tau decays. While not yet conclusive, these deviations hint at possible "new physics" affecting tau interactions.

If such new physics exists, its effects could also appear in other processes, such as the decay $B_c^+ \rightarrow \tau^+ \nu_\tau$. In this decay, a particle containing charm and bottom quarks transforms into a tau lepton and a neutrino. While not rare, this decay is difficult to detect: the tau is heavy and extremely short-lived, and the neutrino escapes detection.

In this thesis, I investigate the feasibility of observing for the first time the decay $B_c^+ \rightarrow \tau^+ \nu_\tau$ by exploiting the unique capabilities of the recently upgraded LHCb experiment at CERN. Achieving this first observation would represent an important experimental milestone and could offer valuable insights into physics beyond the Standard Model.

Also read this article on the LHCb experiment.