Proposed type of solar neutrino spotted

Long-sought particles confirm a fusion reaction that helps power the sun

In a technical tour de force, physicists have spotted long-sought low-energy neutrinos zipping from the sun. The discovery confirms one of the first possible steps in the fusion cycle that helps power the star, says Cristiano Galbiati, a physicist at Princeton University and member of the large international team that reports the discovery February 2 in Physical Review Letters.