a Study of Transverse Momentum and Jets Using Forward Hadrons and Photons in Deep Inelastic Muon Scattering at 490 Gev/c.

The transverse momentum and energy-flow properties of forward (x_{F} > 0) charged hadrons and photons in deep inelastic muon scattering at 490GeV/c have been studied. Single particle transverse momentum and average transverse momentum as a function of x_{rm Feynman} are presented. Events are found to have a planar structure and transverse momentum spectra in and out of the event plane are presented. Data in the kinematic range Q ^2 > 3GeV^2/c^2 and 20 < W < 30GeV/c^2 are used to search for two jets of particles in the forward direction. Energy and particle flow within the hadronic event plane are presented with several different cuts made on the data. A jet reconstruction algorithm is applied and properties of the forward jets are studied. For all plots, comparison is made with predictions from the Lund Monte Carlo tuned in different fashions. It is found that it is necessary to include hard QCD processes (gluon bremsstrahlung and photon-gluon fusion) in order to achieve good agreement between the data and the Monte Carlo. In addition, it is shown that the data have more multi-jet events than predicted by the default version of the Lund (4.3) Monte Carlo. It is suggested that it is necessary to increase the overall 'jettiness' by either increasing the primordial gluon distribution of the nucleon or adjusting the production cross section in the Monte Carlo. The possibility of an increased gluon distribution is presented and compared to data.