Proposal to Measure the Efficiency of Electron Charge Sign Determination up to 10 GeV in a Magnetized Liquid Argon Detector ($\mu$LANNDD)

The recent dramatic success of the ICARUS 300-ton liquid-argon time-projection-chamber prototype [1] indicates that it is timely to review the possibilities for large-scale application of this technology for accelerator-based neutrino physics, neutrino astrophysics, and proton decay [2, 4, 3, 5]. A full exploration of the MNS neutrino mixing matrix (and extensions if sterile neutrinos exist) should be possible if the large mixing angle MSW solution to the solar neutrino problem, presently favored by the data [6], is confirmed by future measurements. A large detector for this purpose should be able to distinguish the charge of the lepton into which the neutrino converts, for which the detector should be immersed in a magnetic field. The most promising option for a large detector that can distinguish the charge of an electron is magnetized liquid argon [7, 8]. However, all studies to date of liquid argon detectors suitable for neutrino physics [9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20] have been in zero magnetic field. We propose to study two key issues with a liquid argon detector of size 0.7× 0.7× 3.0 m, sufficient to contain an electromagnetic shower, placed in a 120D36 magnet in the AGS A3 beamline: