Open Access Dissertation
Date of Award
Physics and Astronomy
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.
Gollapinni, Sowjanya, "Search for contact interactions in the dimuon channel in p-p collisions at sqrt(s) = 7 tev at cms" (2012). Wayne State University Dissertations. 541.