Carnegie Mellon University
My primary research interest is in searches for new phenomena beyond the standard model of particle physics, and particularly signatures with photons and leptons. I am currently leading three groups in CMS searching for new physics in Run 2 via final states with photons. One is a search for events with two photons and significant missing transverse energy (MET), considered a classic channel for gauge mediated supersymmetry (SUSY). The other is a search for events with a photon and a lepton, of particular interest in most SUSY models because it provides the ability to probe the branching fractions of new electroweak particles. The fact that both these analyses are coordinated through the LPC makes it possible to characterize the sensitivity of these searches in terms of the ewkino mixing, and if Run 2 sees evidence of new physics in these channels we will be in a unique position to make early measurements of these parameters.
The assumption of the presence of large MET omits signatures of many more exotic models of new physics, and I have long been interested in these ideas, with a particular focus on the mechanism of stealth SUSY, which translates events with high MET into events with large hadronic energy in a roboust and natural way. I have built a group at the LPC whose purpose is to address this class of models in both diphoton and dilepton final states, and we are currently expanding to incorporate lepton + photon final states with low MET.
Whether new physics is observed soon or requires extended effort, the high luminosity upgrade to the LHC will be vitally important to fully exploit the physics potential of the collider. I have been particularly involved in the development of the high-granularity calorimeter (HGCAL), a proposed design for the endcap calorimetry featuring highly instrumented silicon enabling very precise measurement of forward physics objects. I am responsible for the testing of the properties of the prototype silicon sensors and have contributed to the test beam experiments conducted at Fermilab.
My interest in photons has heavily informed my role in the collaboration. In the past I have acted as the photon expert liason to the SUSY PAG, responsible for coordinating photon identification between the egamma and SUSY groups, and I spent several years as the Monte Carlo production contact for both the ECAL and egamma groups. I have also been active in the LPC for many years, serving as a member of the LPC Events Committee and a co-chair of the LPC Coffee Hour Committee.