This award will provide three year support for the University of Notre Dame High Energy Physics Group to continue its exploration of the energy frontier with accelerator-based experiments, particularly the D0 experiment at Fermilab and the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. Besides extensive hardware contributions and detector commissioning and operations, the physics objectives of the Notre Dame program are broad and will exploit the available data to study top physics, electroweak bosons W and Z, QCD processes, and to search for evidence of electroweak symmetry breaking and other new phenomena. The educational objectives are not only to train postdoctoral researchers, graduate and undergraduate students to be particle physics professionals but, in addition, to make significant efforts to engage non-traditional participants, high school teachers and high school students, in immersive research experiences at the scientific frontier. This award will provide support for innovative outreach activities and allow the Notre Dame group to maintain its leadership in outreach programs. It is one of the four institutions leading the QuarkNet project, hosts one of the Education Leaders in the Interactions In Understanding the Universe (I2U2) project, and provides support for the USCMS Education and Outreach Coordinator.
The goal of particle physics is to understand nature at its most fundamental level. In our experiments we study the basic constituents of matter – the particles – as well as the forces that govern their behavior. All of the experimental results over the past few decades are well described by our "Standard Model" of particle physics, including the recent discovery at CERN of the Higgs Boson. But we know that the Standard Model is incomplete, and that there must be new particles and perhaps new forces not yet discovered. This grant supported the research of the University of Notre Dame experimental particle physics group working at the Large Hadron Collider (LHC) at the CERN laboratory just outside Geneva, Switzerland. Notre Dame is a member of the CMS collaboration, one of two large all-purpose experiments studying the collisions of protons at the world’s highest energies. The group supported during this period included five teaching and research faculty; 17 graduate students, 8 of which earned their doctorate; three research faculty; and two postdoctoral researchers. A large number of undergraduate physics majors also worked with our group during the past several years, with many going on to graduate programs in particle physics. During this grant cycle the Notre Dame group made a number of significant contributions to CMS in several different areas, including physics analysis, software development, computing, detector operations, and research and development for future CMS upgrades. Faculty and students played a key role in the Higgs discovery, in particular in the analysis of the Higgs boson decaying to two photons. Since the discovery of the Higgs there has been a great deal of effort to determine if this particle’s properties are consistent with the predictions of the Standard Model, and our group has been heavily involved in this work as well. There are two main thrusts to this work – one is the measurement of the Higgs decay rates to tau leptons and the other is a determination of the Higgs coupling to top quarks via the measurement of the associated production of Higgs bosons with top quark pairs. Our group has a leadership role in the effort that provides a detailed, accurate simulation of the CMS detector. Particular emphasis has been on simulating the effects of event pileup that will occur at the higher beam luminosities planned for future LHC running. Notre Dame faculty and students have worked with the university’s Center for Research Computing to develop and maintain a Tier 3 computer cluster on campus. This cluster provides our group’s computing needs and excess capacity is also used by the broader CMS community. To optimize the detector for future running at higher energies and higher intensities, CMS has begun work on a two-phase upgrade program. The Phase I upgrade project is already well underway and the Notre Dame group has important responsibilities for key parts of this project. Notre Dame faculty members have management roles in the Phase I upgrade and our technical staff will provide the procurement, fabrication and testing of new detector components for the upgrade. We are also leading the development of one of the two forward calorimeter options for the Phase 2 upgrade. During this past grant period the Notre Dame group continued to strongly emphasize the broader impacts of our research activities. Notre Dame faculty serve as co-PIs of the national QuarkNet program that has brought particle physics to thousands of high school teachers and students over the past 15 years. There are currently more than 50 QuarkNet centers spread across the United States and Puerto Rico. We also serve as mentors for our own active local QuarkNet center, where typically a dozen teachers and 15 students join us in research each summer. Notre Dame faculty helped to lead the effort to make a subset of LHC data available to the public, and now analysis of that data is one of the activities offered to QuarkNet teachers and students. We have also worked with both CMS and ATLAS to extend the reach of particle physics "masterclasses" by organizing and offering these classes to locations in Central America and the Caribbean. In addition to our organized outreach activities, Notre Dame faculty bring particle physics to the non-experts via a number of public lectures and other events. Recently, the movie Particle Fever was shown on campus, followed by a panel discussion with members of our particle physics group.
