  We have investigated light nuclei pair photoproduction in relativistic heavy
ion ultraperipheral collisions. As a first attempt, we employ our previously
developed quantum electrodynamics model, which incorporates a wave-packet
description of initial nuclei, to compute the cross section for
proton-antiproton pair photoproduction. The effective vertex for the photon and
proton interaction is chosen based on studies of two-photon exchange effects in
hadron physics. We present the transverse momentum, invariant mass, and
azimuthal angle distributions of proton-antiproton pairs at $\sqrt{s_{NN}}=200$
GeV in Au+Au ultraperipheral collisions. We observe a $\cos(2\phi)$ modulation
and an almost negligible $\cos(4\phi)$ modulation in the azimuthal angle
distribution. Our studies helps us better understand the matter generated by
light.
