Particle Theory for High-Energy Collider Physics

This award funds the research activities of Professors Nikolaos Kidonakis and Marco Guzzi at Kennesaw State University.

This research project focuses on aspects of theoretical particle physics relevant to the Large Hadron Collider (LHC) and future high-energy colliders. By colliding protons at higher energies than have ever been previously explored, physicists expect to learn more about the fundamental particles of matter and their interactions. Among such fundamental particles, the top quark is the most massive elementary particle that has been discovered, and thus it is a central part of the physics program at the LHC.

Another particle, the so-called "Higgs boson", is involved in the mechanism through which many of the elementary particles gain their masses, and the determination of the properties of the Higgs boson is a high priority. Likewise, a precise estimate of the structure of the proton is critical in understanding the details of proton-proton collisions. All of these questions will be investigated by Professors Kidonakis and Guzzi.

In particular, this research will involve state-of-the-art calculations which will improve theoretical predictions for the production of top quarks and the Higgs particle, and which will increase our knowledge of the structure of the proton. The project will thus advance the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of elementary particles and their interactions, and the search for new physics.

The results of this research will be widely disseminated through publication in refereed journals and presentations at international conferences and workshops. This project will also have significant broader impacts. It will involve students as well as a postdoctoral researcher in fundamental research, and thereby provide critical training for junior physicists in this field. Outreach activities in the wider community will promote knowledge of physics to the public.

More technically, the goal of the research project is to develop and implement formalisms that can improve theoretical predictions of higher-order QCD corrections for a large number of processes at the LHC and future colliders as well as the determination of parton distribution functions (PDFs) in the proton. Resummations of soft-gluon corrections will be performed for total and differential cross sections for processes involving top quarks, including processes with three-particle final states in single-particle-inclusive kinematics such as top production in association with electroweak and Higgs bosons, and other processes in the Standard Model and in models of new physics.

Soft anomalous dimensions will be calculated for various processes to three-loop accuracy. Moreover, these precision calculations will be used together with selected high-precision hadron collider measurements in dedicated global QCD analyses to constrain heavy-flavor PDFs. Heavy-flavor schemes and factorization theorems in hadronic collisions will be studied, and the impact of processes that involve heavy-quark production in association with a vector boson on the determination of heavy-quark PDFs will be explored.

All of these calculations are important for precision studies of the top quark and the Higgs boson, for the exploration of electroweak symmetry breaking and the search for new physics at the LHC and future colliders, as well as for deeper knowledge of the content of the proton, which is a dominant source of uncertainty in precision hadron collider physics.

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.