Nonresonant contributions in B→ρπ decay

We consider nonresonant contributions in the Dalitz-plot analysis of B→ρπ→π⁺π^-π⁰ decay and their potential impact on the extraction of the Cabibbo-Kobayashi-Maskawa parameter α. In particular, we examine the role of the heavy mesons B* and B₀, via the process B→π(B*,B ₀)→π⁺π^-π⁰, and their interference with resonant contributions in the ρ-mass region. We discuss the inherent uncertainties and suggest that the effects may be substantially smaller than previously indicated.