First solar neutrino results from the Sudbury Neutrino Observatory

by Art McDonald (Director of the Sudbury Neutrino Observatory Institute,and Queen 's University,Canada)

Friday 20 Jul 2001, 16:30 → 17:30 Europe/Zurich

500/1-001 - Main Auditorium (CERN)

Solar neutrinos from the decay of ⁸B have been detected at the Sudbury Neutrino Observatory (SNO)via the charged current (CC)reaction on deuterium and by the elastic scattering (ES)of electrons.The CC reaction is sensitive exclusively to n_e's, while the ES reaction also has a small sensitivity to n_µ's and n_t's.The flux of n_e's from ⁸B decay measured by the CC reaction rate is f^CC(n_e)=1.75 ± 0.07(stat.)+0.12 / -0.11(sys.) ±0.05(theor.) ¥ 10⁶cm^-2 s^-1. Assuming no flavor transformation,the flux inferred from the ES reaction rate is f^ES (n_x)=2.39 ± 0.34(stat.)+ 0.16 / -0.14(sys.) ¥ 10⁶ cm^-2 s^-1. Comparison of f^CC(n_e) to the Super-Kamiokande Collaboration 's precision value of f^ES(n_x) yields a 3.3 s difference,providing evidence that there is a non-electron flavor active neutrino component in the solar flux. The total flux of active ⁸B neutrinos is thus determined to be 5.44 ± 0.99 ¥ 10⁶cm ^-2 s^-1,in close agreement with the predictions of solar models.

Organiser(s): Jasper Kirkby/EP Division

Note: Tea & Coffee will be served at 16:00hrs