Theoretical Particle Physics

LHC and flavour physics phenomenology

LHCb physics

LHCb is the dedicated B-physics experiment at the LHC at CERN and is now collecting data. If there is new physics at the TeV scale then it should affect a number of LHCb observables including leptonic, semileptonic, and hadronic decays. In fact, there are some indications in present data, mainly from the Tevatron on B_s mixing, of a deviation from the Standard Model; LHCb will clarify this issue one way or another. We are consolidating, developing, and applying methods to exploit the LHCb results in a bottom-up way.

This research is supported by the STFC under special programme grant ST/H004661/1 “Connecting LHCb to theories of the weak scale.”

BSM phenomenology

The phenomenology of theories beyond the Standard Model (BSM) allows to test them and discriminate them through experiments -- and we are also interested in their refinement based on experimental constraints/signals.

This logically fits together with the previous topic. Currently, we are studying both extra-dimensional and supersymmetric models, with a view to both collider signatures and indirect observables.

Effective field theory techniques and precision calculations

Almost every particle physics observable that is relevant to the new-physics search receives "background" contributions from Standard Model dynamics (usually mainly QCD). The two main tools are
    • effective field theory, to separate (factorize) physics at different distance scales (new physics, weak scale, QCD scale) in order to simplify calculations and control nonperturbative contributions and
    • perturbation theory, to compute contributions from scales where the running QCD coupling is not too large
and we apply them to a variety of setting, mainly in connection with the two previous items.

Related members

Andrea Banfi, Xavier Calmet, Stephan Huber, Sebastian Jaeger, Veronica Sanz