Effective field theory of the electroweak sector

Mebane, Harrison

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https://hdl.handle.net/2142/44370 Copy

Description

Title

Effective field theory of the electroweak sector

Author(s)

Mebane, Harrison

Issue Date

2013-05-24T22:09:15Z

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

Willenbrock, Scott S.

Doctoral Committee Chair(s)

Stelzer, Timothy J.

Committee Member(s)

• Willenbrock, Scott S.
• Neubauer, Mark S.
• Eckstein, James N.

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• effective field theory
• electroweak
• anomalous couplings
• unitarity
• one-loop

Abstract

Effective field theory is a model-independent way to search for indirect effects of new physics. It has many advantages over the traditional anomalous couplings framework. In particular, gauge invariance makes possible the calculation of loop corrections. Furthermore, the issue of unitarity violation is shown to be irrelevant in an effective field theory. There are nine dimension-six operators which generate corrections to precision electroweak quantities through gauge boson propagators. I start with an analysis involving just two operators contributing at one loop in which I show that loop calculations, and the renormalization program in particular, can be carried out in a straightforward manner using effective field theory. I compare this to previous analyses and show that the methods presented here yield more accurate bounds on loop-level operator coefficients. I finish with a global analysis of the full set of nine operators. Bounds are presented on the linearly-independent combinations of the operators. The four operators which affect precision electroweak observables at tree-level are shown to absorb all divergences from the five operators contributing only at loop-level. The bounds are found to be considerably weaker than existing bounds from collider data.

Graduation Semester

2013-05

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http://hdl.handle.net/2142/44370

Copyright and License Information

Copyright 2013 Harrison E Mebane

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