Party Call Physics: likelihoods and classifiers

by Giordon Stark (U. of California, Santa Cruz)

Friday 16 Sep 2022, 11:15 → 12:15 Europe/Stockholm

Abstract: Communicating results between experimentalists and theorists in particle physics has been long and varied. From efficiency maps to selection cut flows - the collaboration between the two communities has continued to grow and evolve. Now, particularly more than ever, a stronger effort has been led within the ATLAS Collaboration taking advantage of the existing technologies used, such as containerization and plain-text data formats, to make analyses fully reproducible. One such data product from an experimental analysis relies on the statistical model used to derive the results published in papers, and these statistical models are essential information for analysis preservation and reuse. The ATLAS Collaboration is starting to publicly provide likelihoods associated with statistical fits used in searches for new physics. These likelihoods adhere to a specification first defined by the 𝙷𝚒𝚜𝚝𝙵𝚊𝚌𝚝𝚘𝚛𝚢 p.d.f. template. This talk will focus on how these statistical models came about, the technical developments to make this possible, and illustrate how detailed information on the statistical modeling can enhance the short- and long-term impact of experimental results.

Bio: Dr. Giordon Stark is a Deaf post-doctoral, experimental particle physicist involved with the ATLAS collaboration at the Santa Cruz Institute for Particle Physics, at UC Santa Cruz. He earned his PhD in Physics from University of Chicago in 2018, and a B.S in Physics from Caltech in 2012. Giordon's research focuses on looking for signs of physics Beyond the Standard Model with a particular interest in Electroweak Supersymmetry and hadronic final states. He is also passionate about boosted object reconstruction, jet substructure, pile-up mitigation techniques, designing robust hardware triggers, the intersection of particle physics & machine learning, and more! Through these efforts, Giordon has also made core contributions to improving the communication of physics results between the ATLAS Collaboration and particle physics theorists and phenomenologists. He also led a group of physicists within the experiment to combine and summarize the results of many BSM searches, providing key insights for the future of the successful ATLAS SUSY search program. These results will be made public later this year. When Giordon is not busy trying to prove the existence of SUSY, he can be found in the kitchen proving sourdoughs, baking pavlovas, and anything else he can get his hands on.

20220916_LundSeminar.pdf