Winner of the 1969 Nobel Prize in Physics and driving force behind the theory of quarks, Murray Gell-Mann (L), pictured in 2011, has died at 89. AFP PHOTO
WASHINGTON, D.C.: Murray Gell-Mann, a physicist who theorized the existence of the quark and won a Nobel Prize for his method of classifying particles, has died at age 89, the California Institute of Technology (Caltech) said.