Access Type

Open Access Dissertation

Date of Award

January 2012

Degree Type


Degree Name



Physics and Astronomy

First Advisor

Paul E. Karchin


The standard model (SM) fails to explain the variety of observed quark and lepton flavors and their masses suggesting that there might exist a more fundamental basis. If quarks and leptons are composite

particles made up of more basic constituents, a new physics

interaction in the form of a four-fermion contact interaction

arises between them. Experimentally the signal is manifest as

a deviation from the SM prediction in the high-mass tail for

the invariant mass distribution of the opposite-sign dimuon pairs.

The Large Hadron Collider (LHC) experiment at the Center for

European Nuclear Research (CERN) is built to explore new physics

possibilities from proton-proton collisions occurring at the

world's highest center-of-mass energy. This thesis

discusses in detail a search strategy for a new physics possibility

based on a left-handed current model of contact interactions.

Based on 5.3 inverse femtobarns of 2011 LHC data as collected by the Compact

Muon Solenoid (CMS) detector, exclusion lower limits at 95%

confidence level are set on the compositeness energy scale

for both destructive and constructive interferences of the new physics

with the SM Drell-Yan process. These limits form the most stringent

limits to date and exceed the current published limits significantly.

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