Azimuthal Energy Flow in Deep Inelastic Neutrino Scattering

The azimuthal dependence of the flow of hadronic energy about the momentum-transfer direction in charged-current deep-inelastic neutrino-nucleon scattering is used to study gluon emission and the transverse momentum of partons confined inside the nucleon. A 7-standard-deviation azimuthal asymmetry is observed indicating an average = 0.303 +- 0.041 GeVc.