2) Larry Wai presented results from his study of a 3000 km baseline detector with the Numi ME beamline, upgraded to 4x the intensity. He compared a Minos-like detector with an example of a fine grained detector. His example has passive Iron absorber with emulsion tracking. Since the goal is not to vertex taus, there can be a larger target mass for a given amount of emulsion. He finds that the fine-grained detector is effective at rejecting nu_tau CC events, which is the most difficult background. Also, there is good e/pi0 separation from the good tracking. However, the signal efficiency is only 15%. He found a reach of 2 degrees in theta_13. In the discussion, it was pointed out that the superbeams document assumes a much higher efficiency for a similar background rejection in a liquid argon detector. We should understand the difference, and what a realistic efficiency is. Also, we might want to consider electronic tracking instead of emulsion. What resolution do we need? What are the relative costs? What R&D would be needed? See http://arXiv.org/abs/hep-ph/0101090 for more details.
3) Fritz DeJongh presented results from a study of low-energy beamlines. Thanks to the Boone collaboration for their simulation code, and to Panagiotis Spentzouris and Iannis Kourbanis for help in using it. This code allows us to study the spectra of the components of the neutrino beam, and the visible energy of the various types of neutrino interactions. Signal efficiencies and background rejections are available from the Boone proposal. The initial stage of the proton driver upgrade could provide an intensity 20X that of Boone. By placing a detector off-axis relative to a Boone-like beamline, the neutrino spectrum can be largely restricted to < 600 MeV. This has useful properties for rejecting backgrounds. And, with the low proton energy, the intrinsic beam backgrounds are low as well. With a large water cerenkov detector such as UNO, a reach in theta_13 comparable to that for higher energy conventional beams may be possible. (Of course, at lower energies, one cannot measure the sign of Delta M**2). Also, the beamline may be cheaper and faster to build. There were comments that many more optimizations might be possible. For example, "phase 2" of the new proton driver upgrade envisions a 3 GeV prebooster. If we had the prebooster earlier, could it provide a good neutrino beam?