Survey of charge symmetry breaking operators for dd -> alpha pi0
Abstract
The charge-symmetry-breaking amplitudes for the recently observed d d -> alpha pi0 reaction are investigated. Chiral perturbation theory is used to classify and identify the leading-order terms. Specific forms of the related one- and two-body tree level diagrams are derived. As a first step toward a full calculation, a few tree-level two-body diagrams are evaluated at each considered order, using a simplified set of d and alpha wave functions and a plane-wave approximation for the initial dd state. The leading-order pion-exchange term is shown to be suppressed in this model because of poor overlap of the initial and final states. The higher-order one-body and short-range (heavy-meson-exchange) amplitudes provide better matching between the initial and final states and therefore contribute significantly and coherently to the cross section. The consequences this might have for a full calculation, with realistic wave functions and a more complete set of amplitudes, are discussed.
Keywords
Cite
@article{arxiv.nucl-th/0402021,
title = {Survey of charge symmetry breaking operators for dd -> alpha pi0},
author = {A. Gardestig and C. J. Horowitz and A. Nogga and A. C. Fonseca and C. Hanhart and G. A. Miller and J. A. Niskanen and U. van Kolck},
journal= {arXiv preprint arXiv:nucl-th/0402021},
year = {2009}
}
Comments
REVTeX 4, 35 pages, 8 eps figures, submitted to PRC