Colloquium — David Yu — Hadronic Jets

Speaker: Dr. David Yu (Brown University)

Title:  Hunting for New Physics with Hadronic Jets at the LHC

Abstract:

Since the landmark discovery of the Higgs boson ten years ago, the LHC experiments have pursued an extensive program of searches and measurements to go above and beyond the Standard Model. Searches for new particles decaying to pairs of hadronic jets, or dijets, are a powerful method for new physics searches at hadron colliders, with a long history from the SppS to the LHC. Due to massive backgrounds and limited trigger bandwidths, however, traditional dijet searches at the CMS experiment can only probe masses well above 1 TeV, leaving significant phase space uncovered. In this colloquium, I will describe several innovations developed by CMS to mitigate these limitations and unlock the low mass phase space, probing dijets as low as 10 GeV. These include analysis using trigger-level objects and searching for highly Lorentz-boosted resonances. Notably, the mass range includes the Higgs boson, and the techniques are adapted to search for Higgs bosons decaying to bottom quarks. I will also describe the ingredients that make up these analyses, including the recent Phase-1 upgrade of the CMS hadronic calorimeter.