Search of new physics with boosted higgs boson in hadronic final states with ATLAS detector

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Abstract/Contents

Abstract
The discovery of a Higgs boson at the Large Hadron Collider (LHC) confirms the validity of the Standard Model (SM) in the description of particle interactions at electroweak scale. However, radioactive corrections to the Higgs mass drives its value to the model's validity limit, indicating either extreme fine-tuning or the presence of new physics at higher energy scale. Since 2015, the LHC starts its Run 2 journey with unprecedented center of mass energy of 13 TeV. Along with increase in luminosity, this greatly extends the sensitivity of ATLAS experiment to heavy new particles at TeV scale. In particular, many new physics models beyond the Standard Model manifest themselves through significant coupling to the Higgs boson in decays of new particles to a Higgs boson and other SM particles. In this work, two searches for resonances decaying to either pair of Higgs bosons or a Higgs boson associated with another SM vector boson in all hadronic final states are presented using data collected by ATLAS during Run 2. Due to the heavy mass of new resonance, Higgs boson and W/Z boson can be boosted to large momentum, causing their decay products to be collimated. The dominant H-> bb decay mode also provides a clear signature through displaced vertices. A powerful boosted boson identification technique fully exploiting such jet substructure and heavy flavor information is therefore developed and used in both searches to suppress the dominant multijet backgrounds and largely enhance search sensitivity in particular for very high resonance mass. In the absence of significant excess, new exclusion limits are set on benchmark new physics models.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2017
Issuance monographic
Language English

Creators/Contributors

Associated with Zeng, Qi
Associated with Stanford University, Department of Physics.
Primary advisor Su, Dong
Thesis advisor Su, Dong
Thesis advisor Graham, Peter (Peter Wickelgren)
Thesis advisor Schwartzman, Ariel G
Thesis advisor Tompkins, Lauren Alexandra
Advisor Graham, Peter (Peter Wickelgren)
Advisor Schwartzman, Ariel G
Advisor Tompkins, Lauren Alexandra

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Qi Zeng.
Note Submitted to the Department of Physics.
Thesis Thesis (Ph.D.)--Stanford University, 2017.
Location electronic resource

Access conditions

Copyright
© 2017 by Qi Zeng
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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