Upgrade of the PEP-II Low Beta Optics
  The successful commissioning and operation of the PEP-II asymmetric e+e- collider motivated further studies to increase luminosity. In this paper, we discuss a modification of the PEP-II lattice to reduce the vertical beta function at the Interaction Point (IP) from the design value of 1.5cm to 1.0cm. This could potentially reduce the colliding beam size, increase particle density at the IP and the probability of beam-beam interactions. In this paper, we outline the optics modifications, discuss tracking simulations, and overview machine implementation. 
Y. Nosochkov, M. Biagini, Y. Cai, F.-J. Decker, M.H.R. Donald, S.   Ecklund, A. Fisher, W. Kozanecki, P. Krejcik, A. Kulikov...