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.

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 theories and perturbative calculations. Effective field theories make it possible to separate (factorize) physics at different distance scales (new physics, weak scale, QCD scale) in order to simplify calculations and control nonperturbative contributions. Perturbation theory is designed compute contributions from scales where the running QCD coupling is not too large and apply them to a variety of settings, related either to new physics searches or to extractions of the fundamental parameters of the theory.

Related members

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