This award funded the research activities of Professors Ayres Freitas and Adam Leibovich at the University of Pittsburgh. 

As part of their research, Professors Freitas and Leibovich aimed to develop improved theoretical tools and calculational methods for the robust interpretation of results from current and future experiments, both at the highest-energy colliders, at dedicated experiments searching for dark matter, and gravitational waves detectors. In particular, they developed advanced techniques for identifying a potentially small new physics signal --- an endeavor that requires an extremely precise understanding of known particles and interactions. Furthermore, Professors Freitas and Leibovich investigated the phenomenological implications of various types of dark-matter models, with particular attention to scenarios that will be extremely difficult to probe in most search experiments. To constrain these models, it is therefore crucial to combine laboratory searches with constraints from astrophysics and cosmology. As such, research in this area advances the national interest by fostering the development of basic science within the United States and expanding our knowledge of fundamental physical laws. This project also involved educating several PhD students and a postdoctoral researcher in cutting-edge calculational and analysis tools. Professors Freitas and Leibovich worked closely with astrophysicists and high-energy experimentalists to develop new search and analysis strategies that will aid in the search for new physics and improve the precision and theoretical robustness of our present understanding. Professors Freitas and Leibovich helped to organize workshops and summer schools to disseminate results from modern research to a larger audience of students and young researchers.

More technically, the research program of Professors Freitas and Leibovich can be divided into three main parts: (1) The development a new efficient technique for the calculation second-order radiative orrections, which has been applied to the computation of the key production process for Higgs bosons at e+e- colliders, and a flexible object orienented software library for the dissemination of such higher-order calculations, so that they can be included in experimental simulations and analysis tools. These advances are important for the analysis of precision measurements at the Large Hadron Collider (LHC) and at planned future e+e- colliders. (2) The application of effective field theories, in particular Soft-Collinear Effective Theory and Non-Relativistic General Relativity, for a more flexible description of how a jet of elementary particles fragment into bound states, called hadrons, that are observable in experiments, e.g. at the LHC, and for calculating higher order corrections to gravitational wave emission. (3) An investigation of a varied class of  extensions of the Standard Model, both at colliders and through the impact on early-universe cosmology. Part of this work builds on the increased recent interest in studies of quantum information principles in different areas physics. The research conducted under this grant has helped to understand how quantum information can be investigated in the production and decay of massive elementary particles at colliders, such as the LHC.

This research plan was guided by ongoing and planned experimental particle-physics efforts, and results were made publicly available in a suitable form.

Last Modified: 10/30/2024
Modified by: Ayres Freitas