I am interested in learning how quarks and gluons build the universe. Quarks are the most basic bits of matter which form all other massive particles such as protons, neutrons, pions, and many others (electrons and neutrinos are not made of quarks). Gluons are the carriers of the force which acts between quarks (much the same as photons are the carriers of the electromagnetic force). The whole thing is described by a quantum field theory called Quantum Chromodynamics, or QCD for short. Although it is easy to describe QCD (the whole theory can be written on one line), it embodies many fascinating phenomena. These include color confinement, asymptotic freedom, spontaneous chiral symmetry breaking, important topological features, the quark-gluon plasma phase transition, and the emergence of an entirely new class of matter made of gluons (like atoms made of pure light!). QCD is also widely applicable. It is used in nuclear physics (how the nuclei of atoms are formed and behave), astrophysics (the formation of neutron and quark stars), cosmology (the very early universe is thought to have been a quark-gluon plasma), and hadronic physics (the physics of protons, pions, etc). You can find a pedagogical introduction to particle physics here and an introduction to QCD in an article I wrote for American Scientist

My research concentrates on describing the structure and interactions of hadrons -- those particles which are made of quarks and gluons. I am especially interested in exotics, particles made in whole or in part by gluons. There is an active effort to discover these particles around the world. I am a member of a new $30 million experimental effort (more info) being mounted at Jefferson Lab in Virginia. Gluons are an especially interesting part of QCD because their peculiar properties are thought to underlie many of the interesting phenomena I mentioned above.

I am a member of a vibrant medium energy physics group here at the University of Pittsburgh. Group members include Steven Dytman, Jim Mueller, Frank Tabakin, Vladimir Savinov, students, and postdocs. We also have extensive collaboration with the medium energy group at neighboring Carnegie Mellon University. Our seminar series alternates between Pitt and CMU.

My research is supported by the Department of Energy and I have funding to support students. You can check out possible student projects at this link. These will be constantly changing as discoveries are made and, of course, students are free to follow their own interests as well.

Some Recent Publications

• Options for the SELEX State D_sJ(2632), Phys. Lett. B (2004).
• Short Range Structure in the X(3872), Phys. Lett B588, 189 (2004).
• Coulomb Gauge Model of Mesons,Phys. Rev. C69, 02504 (2004).
• Parity Doubling in the Meson Spectrum, Phys. Lett. B582, 167 (2004).
• Hybrid Meson Potentials and the Gluonic van der Waals Force, Phys. Lett. B582, 172 (2004).
• The Low lying Glueball Spectrum, Phys. Lett. B577, 61 (2003).
• Quark Model Dissociation Cross Sections, Phys. Rev. C68, 014903 (2003).
• Coulomb Gauge QCD, Confinement, and the Constituent Representation, Phys. Rev. D65, 025012 (2002).
• Chiral Extrapolation, Renormalization, and the Viability of the Quark Model, Phys. Rev. Lett. 87, 072001 (2001).

Postdoctoral Associate
Pieter Maris

Graduate Students
John Hilbert
Olga Lakhina

Undergraduate Students
Quentin Bailey (winner of the 2001 Halliday-Resnick Award for Undergraduate Research)
Andrew McQuiston

Former Group Members

Collaborators

Ted Barnes, Oak Ridge National Laboratory
Steve Godfrey, Carleton University
Nathan Isgur, Jefferson Lab
Adam Szczepaniak, Indiana University
Cheuk-Yin Wong, Oak Ridge National University

Memberships

American Physical Society
Union of Concerned Scientists
Sigma Xi
Hall D Initiative at Jefferson Lab
Baryon Resonance Analysis Group
Topical Group on Hadronic Physics
MIT/JLab Lattice Initiative

Some Of My Other Sites

Swanson's Physics Geneology
QCD Exotica
Lake Louise Hockey Team
Physics 0104 web site
Constructing the Universe
The Search for QCD Exotics
Java and Computational Physics
Web-deliverable Special Functions