Speaker: Professor Tao Han (University of Pittsburgh)

Title: “Physics motivations for future colliders”

Abstract:  With the milestone discovery of the Higgs boson at the CERN Large Hadron Collider (LHC), high-energy physics has entered a new era. The completion of the “Standard Model” (SM) implies, for the first time ever, that we have a relativistic, quantum-mechanical, self-consistent theoretical framework, conceivably valid up to exponentially high energies, even to the Planck scale. Yet, the SM leaves many unanswered questions both from the theoretical and observational perspectives, including the nature of the electroweak superconductivity and its phase transition, the huge hierarchy among the masses of quarks and leptons, the nature of dark matter, and the observed matter-antimatter asymmetry, etc. There are thus compelling reasons to believe that new physics beyond the Standard Model exists. We argue that the collective efforts of future high-energy physics programs at the energy frontier and precision frontier hold great promise to uncover the laws of nature to a deeper level. 

Professor Han's Bio:

Tao Han received his PhD from the University of Wisconsin in 1990. He was a Research Associate at Fermilab and a National SSC Fellow until 1993. He joined UC Davis as an Assistant Professor in 1993 and was promoted to Associate Professor II in 1997. In 1998, he returned to UW Madison, was promoted to Full Professor in 2001, and served as co-director for the "Phenomenology Institute" from 2006. In 2011, he relocated to the University of Pittsburgh and presently serves as the founding director of the Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC). He was named Distinguished Professor of High Energy Physics in 2014. Han's research has focused on new physics at colliders and the phenomenological formulation of theoretical models. He contributed to Higgs physics at hadron colliders, initiating the concepts of "central-jet vetoing," "forward-jet tagging," "cluster transverse mass," etc. He contributed to the formulation for R-parity violating interactions in SUSY, and the Lagrangian field-theoretic description for Kaluza-Klein states in large extra dimensions. He proposed to test neutrino mass generation mechanisms at colliders and other experiments. He has also worked on dark matter studies connecting collider signals with direct and indirect searches. In recent years, he has been involved in exploring physics potentials for future high-energy colliders. Han was elected a Fellow of APS in 2003 and a Fermilab Frontier Fellow in 2004. He is an elected general member of Aspen Center for Physics and of CTEQ. He was 2021 Chair of APS Division of Particles and Fields, Chair for the 2020 APS April Meeting. Han now serves on International Advisory Panels for KEK and Durham University's IPPP.