Vertex detector for super Belle experiment

Using a high resolution silicon vertex detector and a large number of B meson decays, the Belle experiment has succeeded in measuring time-dependent CP asymmetry with high precision. To continue the search for physics beyond the standard model, an upgrade of the KEKB collider to a luminosity of 1035–36cm-2s-1 is proposed. Such a luminosity upgrade will also require an upgraded (“Super”) Belle experiment. Discussions have started on the conceptual design for the silicon vertexing upgrade of this detector. Since the momenta of particles is not high in B factory operating at the ϒ(4S)ϒ(4S) resonance, it is important to avoid high occupancy while keeping the material budget low. A fast data acquisition system and radiation hardness are also required. In this report, the conceptual design of a vertex detector for the Super Belle experiment is shown. The status of R&D topics is also reported.