Steve Biller

Abstract:

Upper limits on the [Formula Presented] flux at the Sudbury Neutrino Observatory have been set based on the [Formula Presented] charged-current reaction on deuterium. The reaction produces a positron and two neutrons in coincidence. This distinctive signature allows a search with very low background for [Formula Presented]’s from the Sun and other potential sources. Both differential and integral limits on the [Formula Presented] flux have been placed in the energy range from 4–14.8 MeV. For an energy-independent [Formula Presented] conversion mechanism, the integral limit on the flux of solar [Formula Presented]’s in the energy range from 4–14.8 MeV is found to be [Formula Presented] (90% C.L.), which corresponds to 0.81% of the standard solar model [Formula presented] [Formula Presented] flux of [Formula Presented], and is consistent with the more sensitive limit from KamLAND in the 8.3–14.8 MeV range of [Formula Presented] (90% C.L.). In the energy range from 4–8 MeV, a search for [Formula Presented]’s is conducted using coincidences in which only the two neutrons are detected. Assuming a [Formula Presented] spectrum for the neutron induced fission of naturally occurring elements, a flux limit of [Formula Presented] (90% C.L.) is obtained. © 2004 The American Physical Society.

Abstract:

A search was conducted for TeV γ-rays emitted from the direction of the ultra-high-energy cosmic ray detected by the Fly's Eye experiment with energy E ∼ 3 × 1020 eV. No enhancement was found at a level of 10-10 cm-2 s-1 for E > 350 GeV. A steady source of ultra-high-energy cosmic ray protons or photons would be expected to produce a γ-ray flux above this level. An upper limit was also set for the flux of TeV γ-rays from 3C 147, the most prominent active galactic nucleus in the error box.

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.