Solar Neutrino Fluxes

Solar Neutrino Fluxes

. Calculated and measured solar neutrino fluxes have consistently disagreed over the past two decades. The fluxes are measured in solar neutrino units, or SNU, defined as one neutrino interaction per trillion trillion trillion atoms, or ten to the thirty-six, per second. Measurements from the chlorine neutrino detector (small dots) give an average solar neutrino flux of 2.55 0.25 SNU (lower broken line). The most recent theoretical calculations (large dots) predict a flux of 8.0 1.0 SNU (upper broken line) for the Standard Solar Model. Other experiments have also observed a deficit of solar neutrinos, suggesting that either some process prevents neutrinos from being detected or the method by which the Sun shines differs from that predicted by current theoretical models.

Copyright 2010, Professor Kenneth R. Lang, Tufts University