Steve Biller

Abstract:

The Sudbury Neutrino Observatory is a 1000 T D2O Cerenkov detector that is sensitive to B-8 solar neutrinos. The energy, radius, and direction with respect to the sun is Measured for each neutrino event; these distributions are used to separately determine the rates of the charged current, neutral current and electron scattering reactions of neutrinos on deuterium. Assuming an undistorted B-8 spectrum, the nu(e) component of the B-8 solar flux is phi(e) = 1.76(-0.05)(+0.05) (stat.)(-0.09)(+0.09) (syst.) X 10(6) cm(-2)s(-1) based on events with a measured kinetic energy above 5 MeV. The non-nu(e) component is phi(mutau) = 3.41(-0.45)(+0.45)(stat.)(-0.45)(+0.48) (syst.) X 10(6) cm(-2)s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(-0.43)(+0.44) (stat.)(-0.43)(+0.46) (syst.) X 10(6) cm(-2)s(-1), consistent with solar models. The night minus day rate is 14.0% +/- 6.3%(+1.5)(-1.4)% of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0% +/- 4.9%(+1.3)(-1.2)%. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution.

Abstract:

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an array of seven 10m aperture telescopes used for gamma-ray astronomy in the 50 GeV to 50 TeV (1 TeV= 10¹² electron Volt) energy range. The gamma rays are detected by measuring the optical Cherenkov light emitted by the cascade of electromagnetic particles that is generated by interactions of the high energy gamma-ray with the Earth's Atmosphere. This paper describes the science goals of the VERITAS array, a description of the array, and expected performance of the instrument.

Abstract:

The Very Energetic Radiation Imaging Telescope Array System (VERITAS) represents an important step forward in the study of extreme astrophysical processes in the universe. It combines the power of the atmospheric Cherenkov imaging technique using a large optical reflector with the power of stereoscopic observatories using arrays of separated telescopes looking at the same shower. The seven identical telescopes in VERITAS, each of aperture 10 m, will be deployed in a filled hexagonal pattern of side 80 m; each telescope will have a camera consisting of 499 pixels with a field of view of 3.5°. VERITAS will substantially increase the catalog of very high energy (E > 100 GeV) γ-ray sources and greatly improve measurements of established sources. © 2002 Elsevier Science B.V. All rights reserved.