The particle physics group of IPhU works towards both obtaining a better understanding of the Standard Model (SM) and probing physics beyond the SM (BSM). Two types of methods to search for BSM physics involve direct detection of new particles as predicted by models such as SUSY, composite Higgs, etc., or precise measurements in the SM sector where deviations from the SM prediction could be linked to the presence of new physics at a higher scale (Higgs couplings, B decays). Measurements relating to Higgs couplings and searches for new phenomena are at the core of the ATLAS-CPPM group physics program, and these will benefit significantly, both from the expected increase in the LHC's luminosity and from the upgrades of the ATLAS detector and subsequent improvement in its performance. Here interplay with the CPT and IFAC-UM theory groups is relevant. For example, in the CPT there is expertise in the construction of strongly-coupled models in collaboration with experts from IFAC-UM, and making predictions for the LHC, and in first principles calculations of nucleon and parton distributions.
However, indirect manifestations of this new physics might already be hiding in heavy-flavor, rare-decay anomalies reported by Babar, Belle and LHCb or in the present and forthcoming precision measurements of the anomalous magnetic moment of the muon. The Belle-CPPM and the LHCb-CPPM groups are heavily involved in measuring rare B and tau decays and in testing lepton universality. Tensions in these sectors will be extensively investigated thanks to the LHC and SuperKEKB data-taking program as well as the upgraded detectors. The CPT and CPPM groups work together closely, focusing on global analyses of measurements determining the heavy flavor physics parameters in the framework of the SM, on studies of precise predictions of sensitive rare decay observables within the SM and on investigations of BSM extensions responsible for possible deviations. Moreover, thanks to their expertise in lattice quantum chromodynamics (QCD), in the phenomenology of the muon (g-2), in perturbation theory and in the building of extensions to the SM, the CPT and IFAC-UM teams will provide the theory needed to determine whether the new (g-2) measurements, at Fermilab and J-PARC, are consistent with SM expectations and, if not, the theory to interpret these results in terms of new, fundamental physics.
At CPT, work is ongoing on constructing models of Dark Matter (DM) and axion-like particles and new DM generation mechanisms. These are testable at experiments such as DarkSide and MadMax, groups that have recently been founded at the CPPM, or via collider signatures detectable at ATLAS. Moreover, such models are probed via indirect searches (see also IPhU astroparticles group) performed at the CTA and Km3net experiments, relying on work done at LAM on the modelling of DM in the universe.
List of the main missions/projects associated to this theme:
- Semileptonic measurements with excited D mesons at LHCb, e.g. R(D**) .
- BSM Physics at the Terascale.
- Dark Matter Models.
- Natural electroweak symmetry breaking with a composite Higgs.
- Type II Seesaw Models.
- Run 3 physics.