IP beam size measurement during collisions at Super-KEKB

We report studies of the direct IP beam size measurement during collisions at the future Super-KEKB asymmetric energy e⁺e^- collider experiment by using e⁺e^- pairs. A large number of e⁺e^- pairs are produced during the collisions and deflected in a strong Coulomb potential made by an oncoming beam. Since the potential depends on the vertical and horizontal beam sizes, the deflected pairs are expected to carry the beam size information, especially in their angular distributions. This IP beam size measurement method has been developed for the future e⁺e^- linear collider experiments, where the huge number of e⁺e^- pairs and the strong Coulomb potential are expected because of their high energy beam collisions. We describe the idea of the application to the beam size measurement at Super-KEKB based on its superior high luminosity, and show the first results of the simulation studies.