This award will provide support to a group working on the ATLAS experiment at the Large Hadron Collider (LHC) at CERN, a particle physics laboratory in Geneva, Switzerland. The LHC machine and ATLAS, a large particle detector facility, were built as basic science tools using funds from NSF and other agencies around the world. One of their primary objectives was to find the Higgs Boson, the last particle in the historically successful "Standard Model" (SM) that accounts for so much of the existence of, and forces between, known particles forming the matter in the universe. This effort has been successful. The next step in the experiments is to look for evidence for physics Beyond the Standard Model (BSM) that might, for instance, account for the presence of the mysterious "Dark Matter" that makes up so much of the mass of the universe. The LHC is currently in the midst of Run 2, at almost twice the energy explored earlier and with significantly increased event samples. It is possible that evidence for BSM physics could emerge at this higher energy and with the higher event statistics.
The investigators from the University of Washington are searching for the new BSM physics through two approaches. The first is through the study of pair production of Higgs Bosons, with each Boson decaying into b-quarks. This work emphasizes specialized analytical techniques for identifying b-quark decays and for background estimation. The second approach is a search for neutral long-lived particles that decay in the ATLAS detector volume far from the LHC interaction point, where the high-energy beams collide. This search uses custom triggers developed by the group to select decays displaced from the collision point and will search for long-lived neutral Higgs bosons as well as a broad range of other BSM phenomena.
The group supports a broader impact program through public dissemination of the results from ATLAS, with emphasis on training students from underrepresented groups.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
