The scientific purpose of the Rare Symmetry Violating Processes (RSVP) project is to observe extremely rare processes that would signal a breakdown of fundamental symmetry laws of the Standard Model (SM) of Elementary Particle Physics. In doing so, RSVP will seek answers to three of the most compelling questions in particle physics: What new particles and fundamental interactions exist beyond the highest energies achievable with the highest energy colliders; what is the origin of the matter-antimatter asymmetry in the universe; and is the degree of CP (charge-parity) symmetry breaking in the K meson and B meson systems the same, as predicted by the SM.
The RSVP project will deploy two types of measurement toward these ends, both of which utilize intense proton beams (provided by the Brookhaven National Laboratory Alternating Gradient Synchrotron) that enable the search for extremely rare processes at a "sensitivity frontier", thus complementing the traditional approach of searching for new particles at the "energy frontier." One approach will search for the direct conversion of a muon into an electron, a process that becomes possible in theories of physics beyond the SM. This subproject is called MECO for "Muon to Electron Conversion." This transition violates lepton flavor conservation and is strictly forbidden in the SM. MECO will observe this process even if only one in 1016 of the muons undergoes the transition, a sensitivity that is more than one thousand times better than previous measurements. If no muon-to-electron conversion is observed at this sensitivity, some of the leading supersymmetric models for physics beyond the SM would be ruled out. Thus, even a negative result would be of great importance.
The second approach employed in RSVP is to observe CP (charge-parity) symmetry breaking in the decay of the long-lived neutral kaon (K0) to a neutral pion (p0), a neutrino, and an anti-neutrino (KOPIO). Only one in 40 billion kaons are expected to decay in this manner. KOPIO is one hundred thousand times more sensitive than previous measurements. A measurement of CP violation in this system will complement and greatly strengthen the many analyses of CP violation in B mesons being conducted in other major experiments around the world. Any difference between CP violation in the K and B mesons would also signal physics beyond the SM. In another important context, the violation of CP symmetry is required to understand the evolution of the early universe into the present matter-dominated universe.
Education and Outreach: KOPIO and MECO are state-of-the-art experiments that address important questions at the frontiers of physics. The potential to leverage RSVP to enhance education at the K-16 levels, to stimulate public interest in science, and to involve underrepresented groups is high. Planning for education and outreach activities is part of the scope of this award.
