In the Standard Model as well as in its Supersymmetric extension, the mechanism proposed to explain electroweak symmetry breaking presents signature particle(s), the Higgs boson(s). This program will cover searches for the Higgs boson(s) at both the Tevatron Collider at Fermilab and the Large Hadron Collider (LHC) at CERN. In particular, the search will be focused on a Higgs decaying into a pair of tau-leptons. The tau -channels offer a clean signature with reduced backgrounds, and are central to the search for all types of Higgs particles such as those deriving from Standard Model, light neutral Supersymmetric, heavy neutral Supersymmetric, charged Supersymmetric theories. Transfer of the expertise from the Tevatron to the LHC will be critical for the success of the Higgs research program of the CMS experiment at the LHC. This proposal will help start a tau -lepton effort within the US part of the CMS Collaboration. Discovering the mechanism responsible for electroweak symmetry breaking and the origin of mass constitutes one of the most important open questions and highest priorities in particle physics today. Fermilab Tevatron and the CERN LHC hadron colliders offer unique discovery opportunities in that front. The PI's research in the last several years has been focused on the quest for the Higgs boson; the signature particle for the prevailing mechanism proposed to explain electroweak symmetry breaking and therefore, brings extensive expertise to the program.
The educational and outreach goals are to engage non-traditional participants, namely female high school teachers and students in particle physics research at the scientific frontier, in the hope to infuse these very young women with a love for physics and science in general. The program will build on the strength of the existing QuarkNet project at the University of Notre Dame, but will extend the project in two new directions: putting the emphasis on young women in science; and extending the participation of high school students and teachers from building hardware to physics analysis of Tevatron data aimed at the discovery of the Higgs boson.
My research funded by this NSF award has been focused on the search for the Higgs particle. I conducted this research at two particle physics experiments: the DZero experiment at the Tevatron proton-antiproton collider at Fermilab, Chicago, Illinois; and the ATLAS experiment at the LHC proton-proton collider at CERN, Geneva, Switzerland. The Higgs particle plays a central role in the best theory we have to describe nature in its tiniest dimensions, what physicists refer to as the Standard Model. Finding the Higgs particle proves the existence of what is called the Higgs field, where other elementary particles acquire mass as they travel through it. More importantly, confirming the Higgs field allows physicists to learn about the universe a billionth of a billionth of a second after the Big Bang, when the four fundamental forces of nature acted as one. We believe that this symmetry between the forces, which existed at the very beginning, broke down as the universe started growing and cooling. By using particle accelerators such as the one at CERN (and previously, the one at Fermilab) to propel particles at very high energies, we expect to see the fundamental forces being unified again. The Higgs is a key piece of the puzzle in this quest for unification. I searched the Tevatron/DZero and the LHC/ATLAS data for signatures of a Higgs particle produced in the collisions and subsequently decaying into either a pair of b-quarks or a pair of tau-leptons. Such signatures can provide evidence for a Higgs as predicted by the Standard Model, but also for Higgs particles predicted by more general extensions of the Standard Model (e.g., Supersymmetry). In the summer of 2012, we discovered unambiguous evidence of a new particle that looks very much like the Standard Model Higgs. The discovery -- arguably the most important discovery in particle physics in the last 40 years -- was made by both the ATLAS experiment and the competitive experiment on the LHC, CMS. We are now working towards measuring the properties of the new particle in order to confirm with certainty that it is the long-sought Standard Model Higgs. In parallel, we are continuing to search for Supersymmetric and other Beyond the Standard Model Higgs particles.
