Photoproduction of neutral pion pairs in the Coulomb field of the nucleus

Abstract

The total cross section for Coulomb photoproduction of neutral pion pairs in the reaction gamma A --> pi0 pi0 A is estimated within the effective chiral lagrangian approach. The amplitude of gamma gamma* --> pi0 pi0 with one off-shell photon is calculated at O(p^6) in the momentum expansion; in addition, nuclear absorption is taken into account. Besides its experimental feasibility, the results of the calculation demonstrate that the reaction gamma A --> pi0 pi0 A is a powerful source of information on the process gamma gamma --> pi0 pi0 close to threshold.

Comments: 18 pages, 6 figures, uses epsf, ioplppt.sty, iopl12.sty (included); Added a discussion of main background from double pion photoproduction on nucleon gamma N --> 2pi0 N via baryon resonance exchange mechanism