Date of Award

Spring 1-1-2018

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

Kevin Stenson

Second Advisor

William Ford

Third Advisor

Senarath deAlwis

Abstract

A search for physics beyond the Standard Model in events with one or more high-momentum Higgs bosons decaying to pairs of b quarks in association with missing transverse momentum is presented. The data, corresponding to an integrated luminosity of 35.9 fb-1, were collected with the CMS detector at the Large Hadron Collider in proton-proton collisions at the center-of-mass energy √s = 13TeV. The analysis utilizes a new b quark tagging technique based on jet substructure to identify jets from Higgs ⟶ decays. Events are categorized by the number of -tagged jets, the mass of the jets, and the missing transverse momentum. No significant deviations from Standard Model expectations are observed. In the context of supersymmetry, limits on the cross sections of pair-produced gluinos are set, assuming that gluinos decay to quark pairs and a Higgs or Z boson, and the lightest supersymmetric particle. The decay chain proceeds through an intermediate particle assumed to be the second lightest in the theory. Assuming a large mass splitting between these two neutral particles, and 100% NLSP branching fraction to Higgs bosons, the lower limit on the gluino mass is found to be 2010 GeV.

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