Adjunct Professor of Physics
Physics Dipl., 1988, Heidelberg University. Ph.D., 1990, Heidelberg University. Research Associate, Heidelberg University, 1990-91. Research Associate, Stanford Linear Accelerator Center (SLAC), 1991-93. Staff Member, CERN, Geneva, Switzerland, 1993-98. Visiting Professor, Stanford University and SLAC, 1999. Adjunct Professor, Physics, Heidelberg University, 1988-present. Professor, Physics, Cornell University, 1999-2008.Chair for Theoretical Physics, Johannes Gutenberg University, Mainz, Germany, 2006-present. Adjunct Professor, Cornell University, 2008-present. Fellow, German National Scholarship Foundation, 1985-93. Research Award, Alexander von Humboldt Foundation, 2005. Fellow, American Physical Society, 2006. Member, Heidelberg Academy of Sciences, 2008. Member, Gutenberg Academy Mainz, 2009. J. Hans D. Jensen Award, 2010. Editor, Journal of High Energy Physics, 1997-present. Editor, European Physics Journal, 1998-present. Editor, Reviews of Modern Physics, 2001-2004.
Heavy-flavor physics and CP violation; effective field theories and renormalization group techniques; quantum-field theories of strong and electroweak interactions; physics beyond the Standard Model; collider physics.
I am pursuing three different lines of research at the moment:
1. Methods from soft-collinear effective theory offer a novel approach to understand factorization and perform resummation of large logarithms for a broad variety of collider-physics processes, such as Drell-Yan and Higgs production, top-quark pair production, and the production of new heavy particles. These applications are studied in detail, and resummation formulae of unprecedented accuracy are derived.
2. Extensions of the Standard Model with a warped extra dimension (Randall-Sundrum models) provide a compelling framework to address at the same time the gauge hierarchy problem and the hierarchies observed in the flavor sector. The implications of such models for new-physics effects in the flavor sector, as well as on electroweak physics and Higgs physics, are explored in great detail.
3. Rare radiative decay processes of B mesons, such as BXs and BXsl+l-, play an important role in testing the flavor sector, extracting CKM matrix elements, and probing for effects of new physics. We have recently discovered a new class of /mb corrections to these processes, which cannot be described in terms of local-operator matrix elements. Instead, they are governed by matrix elements of non-local light-ray operators. The phenomenological impact of these corrections is explored.