Cliff Hargrove

Learn More
Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the D 2 O target. The addition of salt enhanced the signal from neutron capture, as compared to the pure D 2 O detector. By making a statistical separation of charged-current events from other types based on event-isotropy(More)
Cross-sections and angular distributions for hadronic and lepton pair final states in e + e − collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The results are used to measure the energy dependence of the electromagnetic coupling constant α em ,(More)
The measurement of small–angle Bhabha scattering is used to determine the luminosity at the OPAL interaction point for the LEP I data recorded between 1993 and 1995. The measurement is based on the OPAL Silicon-Tungsten Luminometer which is composed of two calorimeters encircling the LEP beam pipe, on opposite sides of the interaction point. The luminometer(More)
Upper limits on the e flux at the Sudbury Neutrino Observatory have been set based on the e 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 e 's from the Sun and other potential sources. Both differential and integral limits on(More)
The Sudbury Neutrino Observatory is a second generation water Cerenkov detector designed to determine whether the currently observed solar neutrino deecit is a result of neutrino oscillations. The detector is unique in its use of D 2 O as a detection medium, permitting it to make a solar modellindependent test of the neutrino oscillation hypothesis by(More)
A search for pair produced scalar fermions with couplings that violate R-parity has been performed using a data sample corresponding to an integrated luminosity of 56 pb −1 at a centre-of-mass energy of √ s = 183 GeV collected with the OPAL detector at LEP. An important consequence of R-parity breaking interactions is that the lightest supersymmet-ric(More)
Production of events with hadronic and leptonic final states has been measured in e + e − collisions at centre-of-mass energies of 130–172 GeV, using the OPAL detector at LEP. Cross-sections and leptonic forward-backward asymmetries are presented, both including and excluding the dominant production of radiative Zγ events, and compared to Standard Model(More)
The light yield of a water-based Cherenkov detector can be significantly improved by adding a wavelength shifter. Wavelength shifter (WLS) molecules absorb ultraviolet photons and re-emit them at longer wavelengths where typical photomultiplier tubes are more sensitive. In this study, several wavelength shifter compounds are tested for possible deployment(More)
A search has been made for sinusoidal periodic variations in the 8 B solar neutrino flux using data collected by the Sudbury Neutrino Observatory over a 4-year time interval. The variation at a period of 1 yr is consistent with modulation of the 8 B neutrino flux by the Earth's orbital eccentricity. No significant sinusoidal periodicities are found with(More)
Gluon jets are identified in e + e − hadronic annihilation events by tagging two quark jets in the same hemisphere of an event. The gluon jet is defined inclusively as all the particles in the opposite hemisphere. Gluon jets defined in this manner have a close correspondence to gluon jets as they are defined for analytic calculations, and are almost(More)