A study of photon-nucleus collisions at high transverse energy

We have measured, for the first time, the atomic number dependence of photon-nucleus collisions at high transverse energy. The measurements were made at FNAL by using a large acceptance calorimeter with 50-400 GeV photons incident on LH$\sb2,$ LD$\sb2,$ Be, C, Al, Cu, Sn and Pb targets. The cross section is parameterized as σ\sb{γ A} = σ\sb{γ p}A\spα, where α is found to increase from 0.9 to 1.1 when the total transverse energy $E\sb{T}$ is increased from roughly 6 GeV to 12 GeV; α is also found to increase with the photon energy at fixed $x\sb{T}\equiv E\sb{T}/\sqrt{s},$ but depends only weakly on the photon energy at fixed $E\sb{T}.$ The increase of α with total transverse energy is qualitatively consistent with previous measurements from the hadron-nucleus collisions, but our α values are somewhat lower. At high transverse energy, photon induced collisions are found to be more jet-like than pion induced collisions, revealing the point-like nature of the photons at high $E\sb{T}.$ The mean planarity in γ A collisions is independent of A in the kinematic range covered by this experiment.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Natural Sciences

Grantor

Rice University

Year dc:date.issued

1993

Author dc:creator

• Zhu, Qiuan

Advisor dc:contributor.advisor

• Miettinen, Hannu E.

• Particle physics
• Elementary particles
• High energy physics

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/16699

OAI identifier oai:identifier

oai:repository.rice.edu:1911/16699