  Beam-beam simulations predict that PEP-II luminosity can be increased by
operating the horizontal betatron tune near and above a half-integer resonance.
However, effects of the resonance and its synchrotron sidebands significantly
enhance betatron and chromatic perturbations which tend to reduce dynamic
aperture. In the study, chromatic variation of horizontal tune near the
resonance was minimized by optimizing local sextupoles in the Interaction
Region. Dynamic aperture was calculated using tracking simulations in LEGO
code. Dependence of dynamic aperture on the residual orbit, dispersion and
distortion of beta function after correction was investigated.
