This award is to fund a proposal submitted to the 2007 OISE Partnerships for International Research and Education (PIRE) competition. It involves a collaboration on the US side between the University of Kansas, the University of Illinois-Chicago, the University of Nebraska, and the University of Puerto Rico-Mayaguez with the Paul Scherrer Institute and Eidgenoessiche Technische Hochschule (ETH) in Zurich, Switzerland.
Intellectual Merit. The US participants propose to build on their existing collaborative experience in the US collaboration responsible for the CMS tracking detector for the CMS experiment at the CERN LHC collider. They are particularly interested in helping to develop a tracking system for the "super LHC," a program of high intensity running of the accelerator with its detectors. The Swiss collaborators have played the lead role in designing and building many key components of the existing Compact Muon Solenoid (CMS) pixel detector experiment. The SLHC will permit nearly compete delineation of the properties of most of the proposed models of electro2weak symmetry breaking in nature. Robust and efficient charged particle tracking in the extraordinarily high event rate and radiation environment of the SLHC collision region will be essential for this physics.
Broader Impacts. The proposal includes extensive international training opportunities for the US graduate and undergraduate students, built on the well-established KU study abroad program. Two of the participating US institutions are from EPSCoR states and a third is a primarily minority institution in Puerto Rico, all of which will involve an important diversity of students in this activity. This project has the potential to be a model for a new mode of internationalized education that would undoubtedly benefit US science students. The project will contribute to a globally engaged and internationally trained workforce, increase minority participation in science and engineering, and develop lasting connections between the participants and their counterparts at foreign institutions. The ability to involve undergraduates is innovative, because in contrast to most high energy physics collaborations, these exchanges will occur with foreign collaborators at the universities, rather than in the laboratory.
Five U.S. university experimental particle physics research groups collaborated with Paul Scherrer Institut and Eidgenoessische Technische Hochschule-Zurich (ETHZ) on pixel silicon detectors for the Compact Muon Solenoid (CMS) Experiment. During the entire grant period from 2007-2014, a total of 7 postdoctoral researchers, 17 graduate students, and 30 undergraduate students travelled to Switzerland and performed research for at least 2 months. Also, a total of 11 students studied for at least a semester at ETHZ. Many of the undergraduate students have graduated and gone into Ph.D. programs. A total of 9 graduate students have obtained either Masters of Ph.D. degrees so far. Over the entire grant period, the CMS collaboration has published over 300 papers in refereed journals including the discovery of the Higgs boson in 2012. The PIRE collaborators were significant contributors to many of these papers including the observance of a rare decay of the Bsubs meson into two muons. The group also searched for new physics beyond the standard model including new vector boson decays, new supersymmetric particles, and recently for events where the top quark appears in conjunction with a Higgs boson. There are still forthcoming publications from the data run which ended in 2012. Students, postdoctoral researchers, and faculty members have presented the results at international conferences including five presentations in the last year. The focus of the research was in preparing a new digital silicon pixel detector to replace the innermost detector in CMS so that subatomic particles can be tracked. A pilot detector was inserted into CMS in the Fall of 2014 in advance of a larger detector to be built and inserted in 2017 (Phase I detector). The students tested the radiation tolerance for this detector and provided simulation tools. Silicon modules have been fabricated with a custom integrated digital chip that has been successfully designed and built as part of this grant. The chips are read out electronically through several components before the data is stored on a computer for further processing at 400 Mbps. Several studies have now shown that this readout scheme will perform at the needed performance levels. A major NSF grant was awarded to members of our PIRE group to help build the Phase I detector.
