Has charge symmetry breaking been observed in the d d -> alpha pi0 reaction?

Abstract

Estimates are made of the d d -> alpha gamma gamma production cross sections in a model where each neutron-proton pair in the beam and target initiates an n p -> d gamma reaction. This approach, which successfully reproduces observables in two-pion production at intermediate energies, suggests that direct two-photon production could provide a very significant background to the measurement of the charge-symmetry-breaking (CSB) reaction d d -> alpha pi0. A non-vanishing CSB cross section has been reported which might be confused with such two-photon production under the given experimental conditions.

Comments: 9 pages, ReVTEX, 2 figures, submitted to Phys. Rev. Lett