Gail G. Hanson
"Gail Hanson and Roy Schwitters are honored for their separate contributions which together provided the first clear evidence that hadronic final states in e+e? annihilation, which are largely composed of spin 0 and spin 1 particles, originate from the fragmentation of spin 1/2 quarks. Gail Hanson observed hadron jets and determined the jet axis by developing and applying the spheric-ity analysis to the hadrons in e+ e? events. She showed that events become more jet?like with increasing energy, contrary to what one expects from a simple phase space production mechanism. Using the beam polarization, she showed that the observed azimuthal distribution of the jet axis was that expected from the production of spin 1/2 quarks that fragment into hadrons."