Dr Michael Teper

Abstract:

We investigate the effects of perturbative branching upon the accuracy with which one can determine the charge of the underlying QCD quantum from the charge structure of a given hadronic jet. We show explicitly how at asymptotic Q² we lose all such charge information. We investigate these effects at current PETRA energies using the Monte Carlo program of Fox and Wolfram; and find that a reasonably accurate charge determination is still possible at these energies. We suggest the variation of the jet charge structure with multiplicity, at a given energy, as a sensitive probe of the onset of perturbative branching inside jets. © 1981 Springer-Verlag.

Abstract:

We point out that over an experimentally important kinematic region lepton pair production arises from the annihilation of a quark and antiquark within the same hadron. This renders incorrect the conventional extraction of structure functions from data in this region. Instead it now becomes possible to obtain information on the correlation between a quark and antiquark within the same proton. We carefully quantify this kinematic region of interest and illustrate it with a discussion of the validity of some recent structure function analyses. © 1980.

Abstract:

We propose a method to identify the parton that gives rise to any particular jet. The method improves with the number of particles in jet, and should indicate which of the jets in a three-jet event at PETRA is the gluon jet. © 1980.

Abstract:

We show that a non-interacting gas of instantons, gives a contribution which vanishes, in QCD, exponentially with N(the number of colours). If we include some of the interactions between instantons, then the resulting dilute gas of instantons-which is now in the form that is used in practice to investigate the structure of hadrons-gives a contribution that is essentialy constant with N. Thus it is entirely consistent for both the N → ∞ limit to be useful and for the dilute gas of instantons to be relevant for the properties of hadrons. © 1980 Springer-Verlag.

Abstract:

We show that the contribution of Drell-Yan dynamics to lepton pair production at fixed x, does not scale with energy, but instead decreases as a power of the energy. There is a transition to a different dynamical picture, and the massive photon now probes the quark-antiquark correlation function of the incident hadron, thus providing a unique handle on this quantity. © 1978.