Study of Hadronic Jets Produced by Charged Pion and Proton Beams Incident on Hydrogen and Aluminum Targets

Author: Yung, Kar Woo

Year: 1980

Degree: Dissertation (Ph.D.)

Advisor: Fox, Geoffrey C.

Committee Member: Unknown, Unknown

Option: Physics

DOI: 10.7907/6kne-3n53

Abstract

High transverse momentum (pꓕ) particles are thought to reflect the underlying parton (quark or gluon) mechanisms of hadron interactions. A particularly simple model by Feynman, Field and Fox (or FFF), involves hard scattering of a pair of partons via gluon exchange (Quantum Chromodynamics or QCD) with subsequent fragmentation of the partons into hadrons.

We present results from an experiment (E260 at Fermilab) on the production of Jets (groups of particles) and single charged particles, at both low and high pꓕ, in 200 Gev interactions. The experiment used a calorimeter triggered multiparticle spectrometer. Results are presented on the comparisons of cross sections and associated charged particle distributions for pion and proton beams and aluminium and hydrogen targets.

Our high pꓕ proton data agree with the FFF predictions in most cases. However, there are signs of discrepancies.

We define ∝ by the equation :

A∝AL = σAL/σAY = where AL is the atomic weight of aluminium and σAL and σAY are cross sections for the aluminium and hydrogen targets. The proton beam data show larger nuclear anomalies (in particular, ∝ > 1) than the pion beam data. There is essentially no difference between π+ and π- beams

We compare the associated charged particle distributions for the two targets. The observed difference between these two targets could be related to the propagation and secondary scattering of partons in the nuclear matter; interpreting our data in this framework, we find that any secondary scattering must be coherent with the main interaction.

E260 is the first experiment to study both high and low pꓕ interactions off nuclear tarqets with detailed measurements of the event structure. This is essential for understanding both nuclear effects and GCD in high energy interactions.

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