|Quantum Field Theory, Elementary Particle Physics|
|Research in Quantum Field theory|
My research is in theoretical particle physics and quantum field theory. Field theory combines quantum theory and relativity and provides the framework for the fundamental theories of particle physics.
I have a longstanding interest in optimizing renormalized perturbation theory in Quantum Chromodynamics (QCD) and other theories. Conventional perturbation theory yields ambiguous results dependent on the arbitrary renormalization scheme choice. The "Principle of Minimal Sensitivity" approach developed in my 1981 paper resolves this issue and has some deep implications. When higher-order calculations became available in the early '90's Mattingly and I showed that optimized perturbation theory, without any extra ad-hoc inputs, predicts "freezing" behaviour at low energies, in accord with many phenomenological indications. I have recently been exploring the mathematical properties of the optimization equations in high orders with the aim of substantiating my conjecture that optimization provides an "induced convergence" mechanism, even though perturbation series in any fixed renormalization scheme are factorially divergent.
Another central theme of my work relates to the nature of the vacuum -- or, in more technical terms, with the dynamics of the scalar field responsible for the spontaneous symmetry breaking that drives the Higgs Mechanism of the Standard Model.
|Graduate: Quantum Field Theory, Classical Dynamics.
Undergraduate: Classical Mechanics, Quantum Mechanics.
P. M. Stevenson, Optimization of QCD perturbation theory: Results for Re+e- at fourth order, Nucl. Phys. B 868 (2013) 38-64.
P.M. Stevenson, Fixed and unfixed points: Infrared limits in optimized QCD perturbation theory, Nucl. Phys. B 875 (2013) 63-79
P. M. Stevenson "The long-range interaction in massless (lambda Phi^4)_4 theory." Modern Physics letters A, 24: 261-271.
P. M. Stevenson, "Hydrodynamics of the Vacuum." Intl. J. Mod. Phys. A, 21: 2877-2903.
P. M. Stevenson "Comparison of perturbative RG theory with lattice data for the 4d Ising model." Nuclear Physics B, 729 (2005) : 542-557.
P. M. Stevenson "How do sound waves in a Bose-Einstein condensate move so fast?." Physical Review A, 68 (2003) : 055601-1-3.
M. Consoli and P. M. Stevenson "Physical mechanisms generating spontaneous symmetry breaking and a hierarchy of scales." International Journal of Modern Physics, A15 (2000) : 133-157.
P. Cea, M. Consoli, L. Cosmai, and P.M. Stevenson "Further lattice evidence for a large re-scaling of the Higgs condensate." Modern Physics Letters, A14 (1999) : 1673-1686.
P. M. Stevenson "Are there pressure waves in the vacuum?." Proceedings of the Second Meeting on CPT and Lorentz Symmetry (2001) : 346-350.
"The vacuum as a medium." University of Houston, Clear Lake, Clear Lake, TX. (1/25/2007)
""Impossible" probabilities and quantum reality,." Families Weekend, Rice University. (9/15/2006)
"Hydrodynamics of the vacuum." University of Pittsburgh, Pittsburgh, PA. (Jan. 6th, 2005)
"Hydrodynamics of the vacuum." University of Bari, Bari, Italy. (June 22nd, 2005)
"Monte-Carlo data for the 4d Ising model: Does it fit the conventional Renormalization-Group description?." University of Catania, Catania, Italy. (June 16th, 2005)
Seminar at University of Catania, Italy
"The long-range interaction in massless lambda phi^4 theory and its RG description." University of Catania, Catania, Italy. (June 2007)
|The vacuum as a medium, PHENO 2002, University of Wisconsin-Madison, April 2002|
|Supervised Theses & Dissertations|
|Syed Asif Hassan, M.S. Effective potential calculation for a nonlocal scalar field theory. (2006) (Thesis or Dissertation Director)|
|Awards, Prizes, & Fellowships|
|George R. Brown Award for Superior teaching, Rice University (May 2012)|