NSF-BSF: Searching for Physics Beyond the Standard Model at the LHCb Experiment

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One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN. However, the Standard Model as it currently exists, leaves open many questions about the universe. These include why matter dominates over anti-matter in the Universe (CP violation), the values of the masses of the fundamental constituents, the quarks and the leptons, the size of the mixings among the quarks, and separately among the leptons, and the properties of dark matter. Most explanations require the presence of new particles, symmetries or forces, which we call Beyond the Standard Model Physics (BSM). This project is designed to pursue searches for BSM physics. The LHC is the premier High Energy Physics particle accelerator in the world and is currently operating at the CERN laboratory near Geneva Switzerland, one of the foremost facilities for answering these BSM questions. The Massachusetts Institute of Technology group is a collaboration member of LHCb, an experiment designed specifically to study the decays of hadrons containing b or c quarks at the LHC and to search for other new states of matter. The goal of LHCb is to identify new physics in nature by examining the properties of hadrons containing these quarks. New physics, or new forces, can be manifest by particles, as yet to be discovered, whose presence would modify decay rates and CP violating asymmetries of hadrons containing the b and c quarks, and thus allow new phenomena to be observed indirectly. Additionally, LHCb is making contributions to the study of the emergent phenomenology of quantum chromodynamics (QCD), and to searches for new GeV-scale (i.e. "low mass") BSM particles, possibly components of the dark sector of matter. And it is in this research domain that the MIT group is playing a leading and fundamental role, both in the development of new trigger strategies based upon machine learning algorithms to identify and select the physics of interest, but also in conducting analyses of interactions that might contain hypothetical "dark sector" particles such as dark photons or axion-like particles. The analytical activities associated with these dark sector studies are enhanced in this program through collaboration with Technion in Israel, through the United States - Israel Binational Science Foundation (NSF-BSF) program.The machine learning algorithms developed by the MIT-LHCb group are available in open-source software packages and are being used by many other research groups. Additionally, the group has introduced at MIT the well-recognized International Masterclasses program, which brings local high school students to the MIT campus to learn about the excitement of high energy physics research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.