The Theoretical Particle Physics group seeks to understand the fundamental forces of nature and the basic structure of matter, energy, and space-time. Work proceeds on theoretical foundations, such as M-theory and string theory, on the interface of particle physics and cosmology, and on phenomenological studies which test, strengthen and extend the current "standard model". Topics of interest include the string theory description of quantum gravity and gauge fields, supergravity, dark matter and dark energy, big bang physics, the origin of flavor and CP violation, the phenomenology of supersymmetry and string theory, QCD, regularization and renormalization in field theories, and the general connection of theory and experiment. The stimulating environment of the Leinweber Center for Theoretical Physics provides a very active atmosphere, support for visitors in all areas of particle theory, and fruitful cross-connections between the particle group and other theoretical disciplines.
Michigan's experimental groups have leading roles in frontier experiments spanning much of particle and nuclear physics. A large Michigan team works on the ATLAS experiment at CERN. The group contributed to the discovery of the Higgs boson and is now studying its properties. It is also pursuing Standard Model (SM) measurements and searching for new phenomena beyond the Standard Model (BSM). Furthermore, the group is engaged in the detector operation and upgrade as well as hosting the ATLAS Great Lakes Tier 2 computing center that disseminates research data throughout the United States.
A Michigan team participates in the KOTO experiment in Japan and the Mu2e experiment at Fermilab. The KOTO experiment aims to discover and measure the rare flavor changing neutral current decay KL → π0νν which has a branching ratio of (2.8±0.4)*10-11 in the SM. The experiment will either establish a stronger limit on the decay or lead to new physics. The Mu2e experiment is designed to search for the neutrinoless conversion of a muon into an electron at a single event sensitivity of 2.87×10-17. The conversion is a charged lepton flavor violation process and would provide evidence of BSM physics.
Michigan physicists also work on the LHCb experiment at CERN, focusing on QCD measurements, in particular how high-energy quarks and gluons hadronize to form the bound-state particles observed in jets.
The neutrino group at Michigan studies how neutrinos interact with matter and mix, using the MicroBooNE and SBND experiments at Fermilab and the JSNS2 experiment in Japan.
Nuclear, particle, and astrophysics at Michigan all benefit from the close relationship between our theory and experimental groups, and all teams look forward to uncovering new knowledge about the fundamental laws governing our universe.