Neutrino Physics & Experiment

Neutrino physics has had an interesting history. In 1930 Pauli postulated the existence of the (electron) neutrino, in 1956 this was confirmed by Reines and Cowan using a nuclear reactor source of antineutrinos. In 1962, a second distinct (muon) neutrino was shown to exist in the experiment at BNL. For that discovery Nobel Prize was awarded to Lederman, Schwartz and Steinberger. In 1995, the third, (tau) neutrino was detected at FNAL. In parallel to those discoveries, Ray Davis' studies of solar neutrinos confirmed understanding of stellar dynamics modulo a 2/3 flux deficit that later was recognized as a result of neutrino oscillations among the three flavors of neutrinos. properties of those oscillations were further unveiled with followup solar, atmospheric, reactor and accelerator neutrino studies . The discovery of oscillations, detection of 19 neutrino events from supernova 1987a by the old IMB and Kamiokande water cerenkov detectors confirmed the theory of supernova explosions and raised new interesting questions about the details of neutrino involvement. The WMAP experiment has started to see imprints of neutrino mass effects on the cosmic microwave background radiation left from the Big Bang.

Introduction

An intense neutrino facility allows probing of the neutrino mixing angles, mass hierarchy, and leptonic CP violation. Physics potential, for making precision measurements of all neutrino oscillation parameters. using a wide band nu_µ beam from BNL , to a (very long baseline) 2540 km baseline (with 0.5 megaton) detector at Homestake Mine in South Dakota was our first study. Potentials of intense neutrino beams from BNL (later from FNAL) to Long Baseline Detectors at Homestake (SD), later Henderson (Co) and Cascades (WA) were studied. Large Detectors located in a low background underground environment(s) would provide additional physics capabilities for proton decay and continuous observation of natural sources of neutrinos such as supernova or other astrophysical sources of neutrinos. The Map shows 3 DUSEL possible underground Detector Sites: HOMESTAKE, HENDERSON, and CASCADES. At present HOMESTAKE is the selected DUSEL Site, and the Detector R & D is underway.

Zohreh Parsa
parsa@bnl.gov
www.neutrino.bnl.gov