Hadron Physics; Heavy Ion Collisions; Quantum Spin Systems
Hadron physics is the study of the properties of strongly interacting "particles", which are actually bound states of fundamental quark and gluon constituents. This field has applications in both high-energy and nuclear physics, indeed one can argue that nuclear physics is a subfield of hadron physics. Calculations of the properties of hadrons employ a theory known as quantum chromodynamics (QCD), but this theory is difficult to study at low energies because of the large strength of these "strong interaction" forces. One either studies models of hadrons, such as the quark potential model, or uses advanced computational techniques such as lattice gauge theory. The results are often rather uncertain, so there is a close interplay between predictions and experiment in this field. Most of the 100s of known hadrons can be described as simple bound states of three quarks "baryons" or quark+antiquark "mesons". However theorists also expect the gluons that bind quarks together to appear in bound states, and the search for pure glue bound states "glueballs" and mixed quark-gluon states "hybrids" is a major experimental activity in modern hadron physics.
Dr.Barnes is a leading theorist in this field, and contributes by deriving the predictions of various quark models and by reviewing recent developments for experimental collaborations, hadron conferences, and even the national media. He was Conference Summary Speaker at MESON2000, HADRON2001, QNP2004, HADRON2005 (theory) and MESON2006 (theory), and has contributed to the physics proposals for HallD at CEBAF, the Tevatron hadron program at Fermilab, DAPHNE at Frascati, CLEO-c at Cornell, the AGS at BNL, and PANDA at GSI/Darmstadt. He has been cited regarding exotic hadrons by the popular media, including the New York Times, CNN and USA Today.
Recently Dr.Barnes has also worked on charmonium-light hadron scattering amplitudes in collaboration with C.Y.Wong (UTK and ORNL) and E.S.Swanson (Pittsburgh) and the research group of D.Blaschke (Rostock); these results are crucial for the interpretation of experimental searches for the quark gluon plasma, using data from the RHIC facility at BNL. At UTK, Barnes is associated with the Fermilab experimental photoproduction group (T.Handler) and the RHIC experimental group (K.Read, S.Sorensen).
Dr.Barnes also has interests in computational condensed matter physics, especially in quantum magnetism, and has collaborated on the development and application of Hamiltonian Monte Carlo methods (as part of the Caltech Hypercube Project) and on extended precision Lanczos methods applied to quantum magnetism in lower dimensions. Quantum magnetism is a field that includes high-Tc superconductivity, and is an area of intense theoretical and experimental work. In this area Barnes and collaborators derived predictions for the behavior of quasi-1D quantum antiferromagnets such as the quantum spin ladder, which has played an important role in recent high-Tc research. These and closely related predictions were used to interpret neutron scattering data from the HFIR at ORNL obtained in collaboration with S.Nagler and D.A.Tennant, which received research awards from ORNL.
Ted Barnes, Group Leader, Theoretical Nuclear Physics (ORNL); Professor of Physics and ORNL-UTK Collaborating Scientist. B.S.E. University of Michigan 1970, M.S. (Physics) Caltech 1973, Ph.D. (Theoretical Physics) Caltech 1977. After pdf and research fellow appointments including the UN Center for Theoretical Physics in Trieste and the University of Kuwait (1977-78), the University of Southampton (1978-79), Rutherford Laboratory (1980-85) and the University of Toronto (1985-89), Barnes joined ORNL and the University of Tennessee in 1989 as the first ORNL-UTK Collaborating Scientist. Dr. Barnes is the author of approximately 100 articles and papers on the physics of hadrons, about 30 papers on computational physics and quantum spin systems, and has collaborated on neutron scattering experiments in this field at RAL and ORNL. He has also served on national review panels and conference committees, especially relating to hadron physics. From 10/2007-10/2009 Dr. Barnes served in the DOE Office of Nuclear Physics, and from 3/2008-5/2009 was responsible for the DOE national research program in nuclear theory. Dr.Barnes is a member of the "Triple Nine" High-IQ Society, which is open to people who are ranked in the top 0.1% in general intelligence tests (IQ 149+). (He only just made it.)