Holographic Pomeron and the Schwinger Mechanism

Understand

We revisit the problem of dipole-dipole scattering via exchanges of soft Pomerons in the context of holographic QCD.

• We show that a single closed string exchange contribution to the eikonalized dipole-dipole scattering amplitude yields a Regge behavior of the elastic amplitude; the corresponding slope and intercept are different from previous results obtained by a variational analysis of semi-classical surfaces.
• We provide a physical interpretation of the semi-classical worldsheets driving the Regge behavior for (-t)>0 in terms of worldsheet instantons.
• The latter describe the Schwinger mechanism for string pair creation by an electric field, where the longitudinal electric field E_L=\sigma_T tanh(\chi/2) at the origin of this non-perturbative mechanism is induced by the relative rapidity {\chi} of the scattering dipoles.