Measurement of the dependence of the light yields of linear alkylbenzene-based and EJ-301 scintillators on electron energy

An experimental test of the electron energy scale linearities of SNO+ and EJ-301 scintillators was carried out using a Compton spectrometer with electrons in the energy range 0.09-3 MeV. The linearity of the apparatus was explicitly demonstrated. It was found that the response of both types of scintillators with respect to electrons becomes non-linear below ~0.4 MeV. An explanation is given in terms of Cherenkov light absorption and re-emission by the scintillators.Comment: 8 pages, 7 figure

Ellipsometric measurements of the refractive indices of linear alkylbenzene and EJ-301 scintillators from 210 to 1000 nm

We report on ellipsometric measurements of the refractive indices of LAB-PPO, Nd-doped LAB-PPO and EJ-301 scintillators to the nearest +/-0.005, in the wavelength range 210-1000 nm.Comment: 7 pages, 4 figure

A Monte Carlo simulation of the Sudbury Neutrino Observatory proportional counters

The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of 3He proportional counters to the detector. The purpose of this Neutral Current Detection (NCD) array was to observe neutrons resulting from neutral-current solar neutrino-deuteron interactions. We have developed a detailed simulation of the current pulses from the NCD array proportional counters, from the primary neutron capture on 3He through the NCD array signal-processing electronics. This NCD array Monte Carlo simulation was used to model the alpha-decay background in SNO's third-phase 8B solar-neutrino measurement.Comment: 38 pages; submitted to the New Journal of Physic

Neutrino oscillations from relativistic flavor currents

By resorting to recent results on the relativistic currents for mixed (flavor) fields, we calculate a space-time dependent neutrino oscillation formula in Quantum Field Theory. Our formulation provides an alternative to existing approaches for the derivation of space dependent oscillation formulas and it also accounts for the corrections due to the non-trivial nature of the flavor vacuum. By exploring different limits of our formula, we recover already known results. We study in detail the case of one-dimensional propagation with gaussian wavepackets both in the relativistic and in the non-relativistic regions: in the last case, numerical evaluations of our result show significant deviations from the standard formula.Comment: 16 pages, 4 figures, RevTe

Low-Multiplicity Burst Search At The Sudbury Neutrino Observatory

Results are reported from a search for low-multiplicity neutrino bursts in the Sudbury Neutrino Observatory. Such bursts could indicate the detection of a nearby core-collapse supernova explosion. The data were taken from Phase I (1999 November-2001 May), when the detector was filled with heavy water, and Phase II (2001 July-2003 August), when NaCl was added to the target. The search was a blind analysis in which the potential backgrounds were estimated and analysis cuts were developed to eliminate such backgrounds with 90% confidence before the data were examined. The search maintained a greater than 50% detection probability for standard supernovae occurring at a distance of up to 60 kpc for Phase I and up to 70 kpc for Phase II. No low-multiplicity bursts were observed during the data-taking period.Natural Sciences and Engineering Research Council, CanadaIndustry Canada, CanadaNational Research Council, CanadaNorthern Ontario Heritage Fund, CanadaAtomic Energy of Canada, Ltd., CanadaOntario Power Generation, CanadaHigh Performance Computing Virtual Laboratory, CanadaCanada Foundation for Innovation, CanadaCanada Research Chairs, CanadaDepartment of Energy, USNational Energy Research Scientific Computing Center, USAlfred P. Sloan Foundation, USScience and Technology Facilities Council, UKFundacao para a Ciencia e a Technologia, PortugalAstronom