Fast-cycling superconducting synchrotrons and possible path to the future of US experimental high-energy particle physics

Abstract

We outline primary physics motivation, present proposed new arrangement for Fermilab accelerator complex, and then discuss possible long-range application of fast-cycling superconducting synchrotrons at Fermilab. MotivationDuring the past decade developments in the neutrino physics combined with progress in the cosmological models of dark matter and dark energy suggest that neutrinos play a very fundamental role in our universe. It has been determined through solar, atmospheric, reactor and accelerator experiments that neutrinos change flavor (oscillate) while passing through matter. This implies that at least two neutrino species have a non-zero mass [1], thus being in a striking contradiction to the Standard Model (SM), and therefore suggesting existence of the physics Beyond the Standard Model (BSM). In addition, the possibility of neutrinos having a small mass may provide a bridge (via e.g. a see-saw mechanism) to the GUT theories including the origin of mass in the universe. As a consequence of this new situation a need for the resolution to the neutrino physics has risen to a level that is not just complimentary to other high-energy particle physics programs but turns out to be absolutely necessary to further the understanding of the microscopic structure and workings of the universe.In neutrino physics phenomenology neutrinos with physical flavors, ν α (α = e, μ, τ), are assumed to be linear super-positions, through a unitarity matrix, of neutrino fields with definitive masses ν i (i = 1, 2, 3). A common parameterization for this matrix uses mixing angles, θ ij = (0, 2π) typically represented by sin 2 θ ij , and a CP-violating phase δ CP = (0, 2π). The current neutrino phenomenology also implies that two of the neutrino species have relatively close masses while the mass of the third one is either much heavier (normal hierarchy) or much lighter (inverted hierarchy) of the "doublet". The lightest (heaviest) neutrino in the doublet is called ν 1 (ν 2 ) and their squared mass difference is defined as δm 2 = m -m > 0. The mass difference between m 3 and m 1,2 doublet is defined as ∆m 2 = |m