Absorption by Double-Centered D3-Branes and the Coulomb Branch of N=4 SYM Theory

Abstract

We calculate the classical cross-section for absorption of a minimally coupled scalar in the double-centered D3-brane geometry. The dual field theory has gauge symmetry broken to S(U(N_1)*U(N_2)) and is on the Coulomb branch of N=4 Super Yang-Mills theory. Our analysis is valid at energy scales much smaller than the W particles mass, giving logarithmic corrections to the cross section calculated at the IR conformal fixed points. These corrections are associated with deformations of the N=4 Super Yang-Mills theory by irrelevant operators that break conformal invariance and correspond to processes where a virtual pair of gauge particles or a virtual pair of W bosons interact with the incident wave to create a pair of gauge particles.