Philip Burrows

Abstract:

We investigate the properties to be expected of jets produced in future accelerators in the TeV energy domain. Current state-of-the-art models for perturbative jet evolution and non-perturbative fragmentation are used together with experimentally realistic methods for jet reconstruction based on the energy flow pattern in a calorimeter. © 1987 Springer-Verlag.

Abstract:

The lifetime of the Ds meson has been measured using the TASSO detector at PETRA and found to be (5.7-2.6+3.6±0.9)×10-13 s. The method used was to reconstruct fully the decay vertex of the channel Ds→φ{symbol}π±, φ{symbol}→K+K-. © 1987 Springer-Verlag.

Abstract:

KNO scaling of the multiplicity distribution in hadronic final states was originally derived as a consequence of Feynman scaling. We show that in iterative models of hadron production in jets, incorporating Feynman scaling, KNO scaling obtains only in the limit when the width of the multiplicity distribution tends to zero. Within the context of the models currently employed to describe e+e- annihilation into hadrons, the apparent KNO scaling observed is an accidental consequence of effects which violate Feynman scaling. © 1986 Springer-Verlag.

Abstract:

The cross section for the process e+e-→π0+ anything has been measured at an average center of mass energy of 34.6 GeV for π0 energies between 0.7 and 17 GeV. The angular distribution for π0 energies larger than 2 GeV is of the form dσ/dΩ∼1+Acos2θ, with A=1.2±0.5. The ratio of π0 to π± production in the measured energy range is 2σ(π0)/(σ(π+)+σ(π-))=1.13±0.18 The form of the differential cross sections agrees within the errors. The mean π0 multiplicity is 5.8±0.9. © 1986 Springer-Verlag.

Abstract:

We show experimentally that an effect of motion of ions, observed in a plasma-based accelerator, depends inversely on the plasma ion mass. The effect appears within a single wakefield event and manifests itself as a bunch tail, occurring only when sufficient motion of ions suppresses wakefields. Wakefields are driven resonantly by multiple bunches, and simulation results indicate that the ponderomotive force causes the motion of ions. In this case, the effect is also expected to depend on the amplitude of the wakefields, experimentally confirmed through variations in the drive bunch charge.