The longitudinal polarization fraction, fL, of B meson to two vector particles is predicted to be almost 0.9 for tree- and penguin-dominant process by the quantum chromodynamics (QCD) factorization models. However, recent measurements of pure penguin dominant pro- cess such as B+ → φK∗+ and B0 → φK∗0 show fL ∼ 0.5. It is important to study lon- gitudinal polarization fraction of other decay modes such as B+ → K∗+ρ0 to resolve this puzzle. In this analysis, we study the B meson to charmless two body decay B+ → K∗+ρ0 as a penguin dominant decay. In order to measure the branching fraction, longitudinal polar- ization and CP asymmetry of B+ → K∗+ρ0, we used full Belle data sample of 772×106BB ̄pairs collected at the Υ(4S) resonance at the KEKB asymmetric energy e+e− collider.
We performed the Monte-Carlo (MC) simulation for signal study, and also studied back-ground events from e+e− → qqbar, BBbar(b → c), rareB (b → u, d, s), peaking background and non-resonant decays. NeuroBayes package was used to suppress continuum background. We used an unbinned extended maximum likelihood 7-dimensional fit to 7 variables based on MC samples. We prepared 7D fitter to measure branching fraction, longitudinal polarization and CP asymmetry of data. The data will be analyzed using this fitter.