W boson cross sections and single spin asymmetries in polarized proton-proton collisions at [square root of] s =500 GeV at STAR

Understanding the structure of the proton is an ongoing effort in the particle physics community. Existing in the region of nonperturbative QCD, the various models for proton structure must be informed and constrained by experimental data. In 2009, the STAR experiment at Brookhaven National Lab recorded over 12 pb-1 of data from polarized p+p collisions at 500 GeV center-of-mass energy provided by the RHIC accelerator. This has offered a first look at the spin-dependent production of W+(-) bosons, and hence at the spin-flavor structure of the proton, where the main production mode is through d+u (u+d) annihilation. Using STAR's large Time Projection Chamber and its wide-acceptance electromagnetic calorimeters, it is possible to identify the e+ + v (e- + v) decay mode of the W bosons produced. This thesis presents the first STAR measurement of charge-separated W production, both the pseudorapidity-dependent ratio and the longitudinal single-spin asymmetry. These results show good agreement with theoretical expectations, validating the methods used and paving the way for the analysis of larger datasets that will be available soon. In the near future the range of this measurement will be augmented with the Forward GEM Tracker. A discussion of the design and implementation of this upgrade is also included, along with projections for its impact.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2012

Author dc:creator

• Corliss, Ross (Ross Cameron)

Advisor dc:contributor.advisor

• Bernd Surrow.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/79258

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/79258