The proton's longitudinal spin structure studied through the weak interaction in pp collisions

Jumper, Daniel S.

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https://hdl.handle.net/2142/95285 Copy

Description

Title

The proton's longitudinal spin structure studied through the weak interaction in pp collisions

Author(s)

Jumper, Daniel S.

Issue Date

2016-09-22

Director of Research (if dissertation) or Advisor (if thesis)

Grosse Perdekamp, Matthias

Doctoral Committee Chair(s)

Peng, Jen-Chieh

Committee Member(s)

• El-Khadra, Aida
• Abbamonte, Peter M.

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• PHENIX
• proton
• nucleon
• structure
• polarized
• spin
• collider
• longitudinal
• Relativistic heavy ion collider (RHIC)
• W Boson
• Asymmetry
• Single spin
• sea
• antiquark

Abstract

For many years there has been limited knowledge of the spin structure of the proton. The degree to which the antiquarks and gluons of radiative origin inside the proton contribute to the total spin is particularly not well confined. The PHENIX experiment at RHIC has made measurements that have, and will, better confine these spin contributions. One of these measurements, made possible by a series of experimental upgrades, is a study of the single spin asymmetry in W boson production ($A_L^W$) in polarized proton-proton collisions. In this measurement, the parity violating weak interaction serves, compared to than previously used techniques, as a cleaner and more direct probe of flavor separated quark and antiquark spin-dependent momentum distributions. This is most significant in the case of the antiquark distributions, which are currently not well constrained. PHENIX has taken data toward this measurement in 2013, analysis of the data was performed, and preliminary $A_L^W$ results have been released. Work is currently underway to finalize these results for forthcoming publication. Once finalized, these results will be included in a global fit along with data from other experiments to reduce the uncertainty of the antiquarks' contribution to proton spin. This dissertation will detail the theoretical basis for this measurement and describe the experimental and analytic procedures used to obtain the result, with special emphasis on contributions from the author.

Graduation Semester

2016-12

Type of Resource

text

Permalink

http://hdl.handle.net/2142/95285

Copyright and License Information

Copyright 2016 Daniel Jumper

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