Diffractive photo-nuclear production of $\rho^0$ mesons in peripheral Au+Au collisions at STAR

Highly Lorentz-contracted electromagnetic fields from fast-moving nuclei can be quantized as linearly polarized quasi-real photons. Photons from one nucleus may scatter coherently off of the other nucleus, and produce vector mesons, such as $\rho^0$. This diffractive interaction creates vector mesons which are (like their parent photon) polarized along the direction of the field and radially away from the nucleus. Coherently produced vector mesons have been previously measured in p+p and Ultra-Peripheral A+A Collisions (UPCs). The $\rho^0$ in UPCs is expected to exhibit quantum interference between the wave functions of the $\rho^0$ from either nucleus. A recent measurement demonstrates this effect in UPCs directly by measuring the angular distribution of the daughter pions. In this talk, we present a complementary measurement by looking for the same photoproduction and quantum interference of $\rho^0$ mesons in 200 GeV peripheral Au+Au collisions at STAR. It is not known to what degree (if at all) the quantum interference might survive the hadronic interactions occurring concurrently in the same Au+Au collision. By measuring such an interference in peripheral Au+Au collisions, one can test the limits of the ``coherence'' of the diffractive process.