Searches for New Physics with Heavy-Flavor Rich Hadronic Final States in the Post-Higgs Era

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Overview: A goal of experiments at the Large Hadron Collider (LHC) at CERN, Geneva, Switzerland is to understand the nature of the Higgs Boson, recently discovered there in 2012, and to discover new physics beyond the Standard Model of Elementary Particle Physics. These goals are relevant to the understanding of the Universe at its most fundamental level in the fleeting fraction of a second just after the Big Bang, and to why we see the Universe as we do now. To meet the challenges of this quest, new theories are advanced, new detectors and accelerators are developed and built, and new computing and analytical methodologies are created, all of which have significant broader impact for the training of young scientists in the near term and the advancement of technological benefits to society over the longer term. The next three years represent a transition of the LHC physics program from a collision energy of 8 Teraelectronvole (TeV) data-taking and operation, to extended operations and data taking at nearly double the energy, 13-14 TeV. Over a thousand scientists from the United States are involved with this scientific program on several major experiments.Intellectual Merit: The research to be conducted under this award to Prof Miller of the University of Chicago and his group is aimed to address deep questions about the nature of the Universe from data collected with the ATLAS experiment, one of the major multipurpose detectors at the LHC. Scientific questions addressed include: Is the newly discovered Higgs particle part of a larger theoretical picture that includes new particles that could be discovered at the new higher collision energy? Why is the observed mass of the Higgs boson so low, found to be 126 billion electron volts, or roughly 135 times the mass of the proton? In fact this low mass value is one of the most profound conundrums in all of science and is currently driving much of the scientific discourse in the field of particle physics. What are the detailed properties of the heaviest of the quarks, the top quark, and the force carriers of the electroweak interaction, the W and Z bosons, at high energy? These questions are critical to our understanding of the full context of the Standard Model of particle physics and to new physics that lies beyond the Standard Model. Technically, Miller and his group will be preparing the ATLAS detector, particularly the calorimetry which measures particle energies, for operations at 13-14 TeV. Analytically, they will be refining their physics analyses on the lower energy 8 TeV data in preparation for new measurements and potential discoveries in the high energy collisions. When the high energy data comes in, the group will focus on searches for supersymmetry through the study of heavily boosted top quarks, which could provide information on extended models of Supersymmetry. Such models, if shown to be valid, are theoretically attractive as they can accommodate the observed low value of the Higgs Mass. Broader Impact: Miller and his group will lead activities will directly benefit the local community in Chicago as well as society at large, both by training students (high school, undergraduate, and graduate) and postdocs, and by enhancing the prominence of Science, Technology, Engineering, and Mathematics (STEM) in the community. A special new outreach program will be established with Lane Tech College Prep High School. The proposed activities include directly mentoring and working with Lane Tech students to bring the excitement felt by High Energy Physicists today into the classroom and to truly stimulate the students using modern, high-tech, and real-life projects in science.