Physics Opportunities with Stage 1 of Project X

Interleaving phases of LBNE and Project Xwill enable pursuit of ever increasing sensitivity to neutrino mixing parameters. Stage 1 of Project X can also enable pursuit of several other physics opportunities in parallel. We survey here the research program for the irst stage of Project X, which is technically advanced enough now to consider it at the same time as Phase 1 of the recon igured LBNE. Most of the physics case for Project X has been discussed elsewhere, for example in Ref. [1], without factoring the program into the three stages of Project X. Here we aim to show how well known and compelling physics questions can be addressed with Stage 1 of Project X. The heart of Project X Stage 1 is a new superconducting 1000 MeV linac that replaces the aging 400 MeV conventional linac in the Fermilab accelerator complex. The accelerator parameters of the Project X Stage 1 complex are described below in Sec. 10. In short, Stage 1 will increase the Main Injector beam power from 700 kW to 1200 kW, the 8 GeV Booster beam power available to shortbaseline neutrino experiments from 25 kW to 42 kW and serve as a powerful innovative proton driver for an upgrade of the Fermilab Muon Campus. This upgrade can be realized with the new linac operating at 100 kW with a 10% duty factor. The core superconducting technology of the new linac can support a very high beam duty factor (continuous wave or CW) and much higher beam power, 1 MW at 1000 MeV, which could be realized with a marginal (15%) increase in cost associated with higher RF power and cryogenics. Amegawatt CW linacwould open the door to an even broader research program for US particle physics. In particular, a megawatt CW linac could support a world-leading program of electron, nucleon, nuclear, and atomic EDM research and nucleon instability research through neutron-antineutron oscillation experiments. With the addition of a compressor ring to optimize proton pulse timing themegawatt linac could also provide aworld-class decay-at-rest neutrino source for next generation short-baseline experiments. The new megawatt linac can also support an important program of materials research and R&D for high reliability proton drivers and targetry necessary for energy applications based on accelerator driven systems. The possibility of leadership-level funding from India could allow Stage 2 to be built at the same time as Stage 1. Realizing Stage 2 of Project Xwould dramatically enhance the physics reach of the rare processes program and support high power (1200 kW) Main Injector operation at 60 GeV which can signi icantly improve the LBNE neutrino energy spectrum. Most of the material presented here is drawn from the recent meeting of the Project X Physics Study (PXPS), which was held at Fermilab June 14–23, 2012, and attracted over 200 participants [2]. Over the next twelve months, the PXPS will develop the physics case for all three stages of Project X in more detail. This appendix is an abbreviated summary of the broad program discussed at PXPS. The research programenabled by the full scope of Project X broadly attacks central issues in the ield today: New physics at the electroweak scale and beyond, origins of lavor, and origins of matter-antimatter