Roger Rusack

My research is conducted at the Large Hadron Collider (LHC) at CERN in Switzerland. I work with data collected at the Compact Muon Solenoid (CMS) experiment, which is one of the two large general-purpose detectors at the LHC, the other being ATLAS. The CMS Collaboration has now collected 130 inverse fentobarns of data at a center-of-mass energy of 13 TeV. After the initial observation of the Higgs boson in 2012 my group has concentrated on measuring precisely its properties and looking for anomalies. Our most recent result for the Higgs boson mass, primarily derived by the Minnesota team, is 125.38 GeV ± 0.14 GeV. This is currently (May 2021) the world's most precise value. In addition to our work on the Higgs boson our group is conducting a search for anomalous couplings between three gauge particles, which, if we were to find them, would be a sign of new physical phenomena. Later in this decade the LHC will be upgraded to the the HL-LHC where the instantaneous luminosity will be increased by a factor of five from its current value. This requires many improvements (or upgrades) to the detector. My group is working on the upgrade of the crystal calorimeter readout to improve it's timing resolution and on the complete replacement of the forward calorimeter systems with an imaging high granularity calorimeter - HGCAL. HGCAL has a littler over six million channels of silicon sensors, which allows for a full three-dimensional image of electromagnetic and hadronic showers to be observed and measured. I also have an interest in the problem of particle detection and the application of new emergent technologies to experimental high energy physics. One of my research interests in this area is the production of an radiation tolerant digitally controlled delay which allows the control of a signal delay with a precision of 200 fentoseconds. Another is the use of modern artificial intelligence tools for event reconstruction.