48 research outputs found
A brief introduction to nonperturbative calculations in light-front QED
A nonperturbative method for the solution of quantum field theories is
described in the context of quantum electrodynamics and applied to the
calculation of the electron's anomalous magnetic moment. The method is based on
light-front quantization and Pauli-Villars regularization. The application to
light-front QED is intended as a test of the methods in a gauge theory, as a
precursor to possible methods for the nonperturbative solution of quantum
chromodynamics. The electron state is truncated to include at most two photons
and no positrons in the Fock basis, and the wave functions of the dressed state
are used to compute the electrons's anomalous magnetic moment. A choice of
regularization that preserves the chiral symmetry of the massless limit is
critical for the success of the calculation.Comment: 7 pages, 5 figures, RevTeX 4.1; to appear in the proceedings of
QCD@Work 2010, Martina Franca, Italy, June 20-2
An illustration of the light-front coupled-cluster method in quantum electrodynamics
A field-theoretic formulation of the exponential-operator technique is
applied to a nonperturbative Hamiltonian eigenvalue problem in electrodynamics,
quantized in light-front coordinates. Specifically, we consider the
dressed-electron state, without positron contributions but with an unlimited
number of photons, and compute its anomalous magnetic moment. A simple
perturbative solution immediately yields the Schwinger result of \alpha/2\pi.
The nonperturbative solution, which requires numerical techniques, sums a
subset of corrections to all orders in \alpha\ and incorporates additional
physics.Comment: 6 pages, 1 figure; RevTeX 4.1; presented at QCD@Work2012, the
International Workshop on QCD Theory and Experiment, June 18-21, 2012, Lecce,
Ital