Particle Fever— The search for new physics
Physicist Marc Weinberg, distinguished researcher from the LHC Physics Center at Fermilab, the United States Department of Energy national laboratory specializing in high-energy particle physics, discusses how Compact Muon Solenoid experiments at CERN's Large Hadron Collider are expanding our understanding of physics and the universe. Presented as part of the 2020 National Week of Science on Screen, in partnership with the University of Iowa Department of Physics and Astronomy.
As the Large Hadron Collider is about to be launched for the first time, physicists are on the cusp of the greatest scientific discovery of all time—or perhaps their greatest failure.
Particle Fever follows six brilliant scientists during the launch of the Large Hadron Collider, marking the start of the biggest and most expensive experiment in the history of the planet, pushing the edge of human innovation. As they seek to unravel the mysteries of the universe, 10,000 scientists from over 100 countries joined forces in pursuit of a single goal: to recreate conditions that existed just moments after the Big Bang and find the Higgs boson, potentially explaining the origin of all matter. But our heroes confront an even bigger challenge: have we reached our limit in understanding why we exist?
About the Speaker
Marc Weinberg's primary research interest is in searches for new phenomena beyond the standard model of particle physics, and particularly signatures with photons and leptons. He is 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, the team 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 Dr. Weinberg has 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. He has built a group at the LPC whose purpose is to address this class of models in both diphoton and dilepton final states, and they 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. Dr. Weinberg has 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. He is responsible for the testing of the properties of the prototype silicon sensors and has contributed to the test beam experiments conducted at Fermilab.