Research Group on Advanced phenomenology of elementary particles and fundamental interactions at large colliders and flavor factories

Description

Theoretical group with internationally recognised expertise in the physics and phenomenology of elementary particles and their fundamental interactions at large colliders (high-energy frontier) and flavour factories (high-intensity frontier). Pioneering group in the application of effective field theories and perturbative methods to higher orders in quantum field theories for the analysis and interprest of experimental data. The group has expertise in the physics of the scalar sector of electroweak theory, electroweak symmetry breaking and Higgs boson physics, strong interactions, heavy quark physics (top and bottom quarks), and the flavour physics of leptons and hadrons.

The group is also notable for its coordination of national and European research networks, and for its involvement in outreach and knowledge transfer activities. The Standard Model (SM) of particle physics is the quantum field theory that describes the strong, weak and electromagnetic interactions of the three families of quarks and leptons. It has been very successful in describing all experimental observations over a wide range of energy scales, from the electron mass to beyond the top quark mass. The recent discovery of the Higgs boson is a major achievement that also opens up new questions in the scalar sector of the theory: is it solely responsible for the spontaneous electroweak symmetry breaking (EWSB) mechanism, what fundamental dynamics explains the hierarchy between the masses of the three families? This is the most important flavour sector, which in the SM includes 20 of the 25 free parameters of the model.

Another question of interest is to explore whether or not there is structure in the current gap between the known states and the Planck scale. In order to discover new phenomena, the possible existence and properties of an extended spectrum of states beyond those included in the SM must be investigated. Recent, ongoing and future experiments such as the Tevatron, the LHC or the Linear Collider (LC) at the high-energy boundary, or the flavour factories (K, D and B) capable of measuring with high precision observables at low energies at the high-intensity boundary, complement each other very well in the search for deviations from the SM predictions that may be able to reveal underlying dynamics. This goal will only be possible if the tremendous experimental effort is matched by a corresponding theoretical work able to match the experimental accuracy. This is a difficult task because theoretical predictions often involve strong interaction effects that are not easy to quantify. Very complex higher-order perturbative calculations are needed to provide accurate theoretical predictions of hard scattering processes at the LHC, while non-perturbative methods are needed to predict low-energy observables in the flavour factories. Not only the quark sector, but also the area of lepton flavour is a field of enormous interest, boosted by the discovery of neutrino masses. The search for lepton flavour violation in flavour factories (LHCb, MEG, SuperBelle) must be complemented with a solid theoretical framework to resolve a possible structure of the theory beyond the SM. Our research goals include current trends integrating LHC physics and present and future flavour factories, with a strong interest towards phenomenology in a future LC.

Goals CT

LHC physics and present and future flavour factories
Theoretical predictions of precision in the Standard Model and beyond the Standard Model.
Effective field theories.
Higgs boson phenomenology and routine models of electroweak symmetry.
Monte Carlo event generators.

Research lines

Top quark physics and new perturbative methods
The top quark is the heaviest known elementary particle and plays a fundamental role in many extensions of the Standard Model. In a hadronic environment like the LHC it is essential to control the effects of the strong interaction (QCD), hence complex calculations in perturbation theory.
Flavour physics: leptons and hadrons
The associated phenomena of flavour-changing processes and CP symmetry violation have profound implications for our knowledge of the Universe and, in particular, are related to the observed large asymmetry between matter and antimatter.
Scalar sector of electroweak theory: physics of spontaneous symmetry breaking and the Higgs boson
The LHC is specially designed to investigate the spontaneous breaking of the electroweak symmetry responsible for the generation of the masses of all particles. The theoretical consistency of the Standard Model requires the existence of a new scalar force field.

Management