Dr. Cameron Bravo
Stanford University
Accelerator Searches for Sub-GeV Dark Sectors
Location: 1080 Physics Research Building
Faculty Host: Chris Hill
Abstract: A new generation of dark matter experiments focusing on sub-GeV Dark Sectors capable of explaining the observed relic abundance have attracted increasing interest over the last decade. One of the most general models with a sub-GeV mediator is a Dark Sector which introduces a new U(1) gauge symmetry, with a corresponding boson called a "dark photon", "heavy photon", or A' (read A prime). The Heavy Photon Search (HPS) is one of the first experiments dedicated to the search for dark photons, specifically in the case that they decay to standard model charged leptons. HPS has successfully completed two physics runs in 2019 and 2021. I will present an estimate of the sensitivity of this data for dark photons and discuss other models the data could also be sensitive to. Meanwhile, a recently proposed project called the Light Dark Matter eXperiment (LDMX) will be sensitive to the production of sub-GeV dark matter particles, such as those with interactions mediated by dark photons. The LDMX detector concept, its rejection of key backgrounds, and sensitivity to new physics will be presented.
Bio: Starting out his career in particle physics through participation in the NSF PIRE program, Cameron spent the summer of 2010 at the Paul Scherrer institute in Villigen, Switzerland. He was invited to return the following summer and stay for 14 months as an exchange student at the Swiss Federal Institute of Technology (ETH Zurich). During this time, he contributed to research and development of the PSI46digi chip used in the front-end of the second-generation pixel detector of the Compact Muon Solenoid (CMS) experiment. He then joined the CMS group at UCLA as a graduate student where he continued contributing to detector R&D work for the Cathode Strip Chamber (CSC) and Gas Electron Multiplier (GEM) sub-systems of CMS. He also wrote new proton-proton collision monte carlo software, called BaryoGEN, for studying Sphaleron/Instanton-like transitions. These simulations were used to develop the first ever dedicated experimental search for sphaleron/instanton transitions of the electro-weak gauge field. He then decided to make a pivot in his career as a postdoc to focusing on accelerator-based searches for thermal relic dark matter models, now working on agile experiments with less than 100 people. He currently serves as the deputy analysis coordinator, software coordinator, and as a member of the executive committee of the Heavy Photon Search (HPS) Collaboration. He hopes to shed some light on dark matter or make a significant case against the thermal relic nature of it.
