Kajita, McDonald win Nobel physics prize

Scientists hailed for work on neutrinos

Takaaki Kajita of Japan and Arthur McDonald of Canada won the Nobel Prize in physics on Tuesday for discovering the "chameleon-like" nature of neutrinos, work that yielded the crucial insight that the tiny particles have mass.

The Royal Swedish Academy of Sciences said the two researchers had made key contributions to experiments showing that neutrinos change identities as they whiz through the universe at nearly the speed of light.