Event-by-event direction reconstruction of solar neutrinos in a high light-yield liquid scintillator
A. Allega (Queen’s University, Department of Physics, Engineering Physics and Astronomy, Kingston, ON K7L 3N6, Canada); M. R. Anderson (Queen’s University, Department of Physics, Engineering Physics and Astronomy, Kingston, ON K7L 3N6, Canada); S. Andringa (Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Av. Prof. Gama Pinto, 2, 1649-003, Lisboa, Portugal); J. Antunes (Laboratório de Instrumentação e Física Experimental de Partículas (LIP), Av. Prof. Gama Pinto, 2, 1649-003, Lisboa, Portugal, Universidade de Lisboa, Instituto Superior Técnico (IST), Departamento de Física, Av. Rovisco Pais, 1049-001 Lisboa, Portugal); M. Askins (Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720-8153, USA, University of California, Berkeley, Department of Physics, CA 94720, Berkeley, USA); et al - Show all 119 authors
The direction of individual solar neutrinos has been reconstructed using the liquid scintillator detector. Prompt, directional Cherenkov light was separated from the slower, isotropic scintillation light using time information, and a maximum likelihood method was used to reconstruct the direction of individual scattered electrons. A clear directional signal was observed, correlated with the solar angle. The observation was aided by a period of low primary fluor concentration that resulted in a slower scintillator decay time. This is the first time that event-by-event direction reconstruction in high light-yield liquid scintillator has been demonstrated in a large-scale detector.
