Measurement of the analyzing power in inclusive, high-x(F) charged pion production with a 200 GeV/c polarized proton beam

The analyzing power, A$\sb{\rm N},$ in inclusive π\sp{+} and π{-} production by a 200 GeV/c polarized proton beam was found to have a striking $x\sb{F}$ dependence in which the magnitude of A$\sb{\rm N}$ increases from 0 to 0.42 for the π\sp{+} data and decreases from 0 to $-0.38$ for the π\sp{-} data for increasing $x\sb{F}$ over the kinematic range $0.2 \le x\sb{F} \le 0.9$ and 0.2$GeV/c \le p\sb{T} \le 2.0GeV/c.$ The higher values of $x\sb{F}$ and $p\sb{T}$ in these kinematic ranges insure that the measured particle came from an interaction of the beam and target through a direct channel and that quark scattering through gluon exchange is the dominant interaction. The charged pions were identified and tracked with a large forward multi-particle spectrometer based upon a Helium gas threshold Cherenkov counter. A simple parton recombination model correctly predicts the signs of the spin parameters measured in this experiment. It also correctly predicts the magnitudes of the π\sp{+} and π\sp\circ analyzing power at high $x\sb{F}$ but the π\sp{-} analyzing power is twice the predicted value. The π\sp{+}, π\sp{-}, and π\sp\circ analyzing powers were also measured with a polarized anti-proton beam. These data and their interpretation with the simple model suggest that the transverse spin of the proton can be correlated with its quarks in certain kinematic regions, however, the details are still not well understood.

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

1991

Author dc:creator

• White, Joseph LaSalle

Advisor dc:contributor.advisor

• Roberts, Jabus B.

• 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/1911/16585

OAI identifier oai:identifier

oai:repository.rice.edu:1911/16585