This is a photo of me in the 27-kilometer long tunnel that contains the Large Hadron Collider, while I was hosting a tour for the U.S. ambassador to Switzerland in June 2014. I like this photo a lot because I very rarely am in the tunnel, or wear a hard hat, or wear a jacket and tie for work, or hang out with ambassadors!
258E Jorgensen Hall
I am an experimental particle physicist, with interests in top-quark physics, weak interactions, and the Higgs boson. I've done research in particle physics for more than twenty five years, ever since I was a college student, and I have to say that this might be the most exciting time in my career to date and possibly for the rest of it, too. The Large Hadron Collider (LHC) at CERN in Geneva, Switzerland started operations in 2009, colliding protons at energies a factor of 3.5 higher than we've ever achieved previously with a particle accelerator. I and other physicists at UNL work on the Compact Muon Solenoid (CMS) at the LHC. In 2012, we observed a new particle, which as far as we can tell is the long-awaited Higgs boson, the last missing particle of the standard model of particle physics. As a field, we spent fifty years looking for it! My own recent contribution to our knowledge about the Higgs is a search for anomalous production of this particle in association with a single top quark. The Higgs discovery is great news, but we also expected to see other new particles by now, and we haven't. That's a problem for a lot of proposed models of particle interactions. During 2015-18, we resumed operations of the LHC at a higher collision energy, 13 TeV in the center-of-mass frame, and we are very hopeful that we will observe something new and exciting. (Unfortunately, no luck yet.) Right now the LHC is shut down for upgrades and maintenance, with collisions expected again in 2021.
Besides the physics of the experiment, I'm also involved in computing issues. CMS produces petabytes of data each year, and it has to be processed, stored, transferred and analyzed. It's a huge computing task, and much of it gets done using facilities here in the United States. In 2015-19, I served as manager of software and computing for the U.S. CMS Operations Program, with responsibility for the $16M annual budget for U.S. CMS computing facilities and support personnel. At UNL, we host a so-called "Tier-2" computing center for CMS, where we host data that collaborators from all over the world analyze, and also run the simulations that help us understand what new phenomena might look like. I interact closely with our colleagues at the Holland Computing Center who look after the day-to-day operations of the computers. There are six other sites like ours in the U.S. (at Caltech, Florida, MIT, Purdue, UC San Diego and Wisconsin), and about fifty of them around the world. I spent nearly a decade as the leader of the team that runs the U.S. sites, and I continue to be a co-coordinator of the world-wide program. From this computing work, I've branched out into some other interesting problems in data-intensive high-throughput computing, such as the NSF-funded "Any Data, Anytime, Anywhere" project that seeks to make data access over the wide-area network transparent and reliable for users, the DIANA-HEP project that is developing innovative software for large-scale data analysis, and the new IRIS-HEP software institute that is enabling computational and data science research for the High Luminosity LHC that will begin operations in 2026.
In Fall 2019 I am teaching Physics 201, a seminar course on physics research targeted at our freshman physics majors
In the past I've taught Physics 212 (introductory calculus-based electromagnetism), Physics 311 (intermediate-level classical mechanics for majors), Physics 441 (advanced experimental laboratory for physics majors), Physics 462 (atomic, nuclear and particle physics for majors) and Physics 926 (graduate-level particle physics).
I am the Chief Undergraduate Adviser for the Department of Physics and Astronomy, and also chair of the department's Undergraduate Committee. This makes me the first point of contact with students for undergraduate academic issues. Our committee oversees advising of physics majors, recruiting, scholarships and the Society of Physics Students chapter. Interested in majoring in physics? Ask me how!
I am a member of the UNL Academic Planning Committee, which helps set the academic goals of the university, and also handles changes in academic programs due to budget cuts. In 2017-18 I was chair of the committee and had a far too large public profile. I also am a member of the College of Arts and Sciences Executive Committee for 2019-20.
In the past I have been chair of the UNL Research Council, and a member of the College of Arts and Sciences Committee on Student Academic Distinction, Awards, and Appeals and the College of Arts and Sciences Research Advisory Committee, and the College of Arts and Sciences Inclusion, Diversity Equity and Access (IDEA) Committee. I am currently the secretary of the campus chapter of the American Association of University Professors.
I was a member of the scientific program committee for the DPF 2015 conference that was held in 2015 (of course!). Earlier, I was a member of the US LHC Users Association Executive Committee in 2013-14, and in 2012-13 I was a subgroup convener for the "Snowmass" Community Summer Study.
More about me
I grew up in South Orange, NJ, and at the time never dreamed that I would live in Nebraska someday. I hold an AB in Physics from The University of Chicago (1992), and an MS (1995) and Ph.D. (1997) in Physics from Cornell University. I was a postdoctoral researcher at The Johns Hopkins University and the University of Michigan before coming to UNL in 2004 as an Assistant Professor; I was promoted to Associate Professor in 2009 and then to Professor in 2016. I was on a faculty development leave for the 2013-14 academic year, and I spent my time in residence at CERN. Since 2015 I have been a Visiting Scientist in the Scientific Computing Division at Fermi National Accelerator Laboratory, which is the host laboratory of the U.S. CMS Operations Program. I worked on the CDF experiment at Fermilab in 1989-92 and 1997-2004, the CLEO experiment at Cornell in 1992-97, and the D0 experiment at Fermilab from 2004 until we tire of looking at the data (still publishing a couple of papers a year!). I am the previous recipient of an NSF Early Career Development Award, and in 2016 I was named a Fellow of the American Physical Society. In 2018-19 I was a Big Ten Academic Alliance Academic Leadershp Program Fellow. I find my job as a university professor to be utterly exhausting but also continually fascinating, and I am very glad to have this opportunity to pursue a wide range of interests.