Study of Branching Ratio And Polarization Fraction in Neutral B Meson Decays to Negative Rho Meson Positive Kaon Resonance

We present the preliminary results on the search for B0 → ρ-K*+. The data sample comprises 122.7 million B(bar B) pairs in the e+e- annihilation through the Υ(4S) resonance collected during 1999-2003 with the BABAR detector at the PEP-II asymmetric-energy collider at Stanford Linear Accelerator Center (SLAC). We obtain an upper limit of the branching ratio at 90% confidence level as Β(B0 → ρ-K*+) < 17.2 x 10-6. The fitted result on the polarization fraction shows no evidence that the decay is longitudinally dominated as predicted by various theoretical models