Uncertainty Study of Bd(Bs) → γνbar nu Decays

B0(Bs) → γν decays are useful to determining the decay constants fB(fBs) and B(Bs) meson wave function. Using the B meson wave function determined in hadronic B(Bs) decays, we study the uncertainties due to the types of B meson wave functions. We find that the branching ratios are sensitive to the type of wave functions and input parameters, but the energy spectrum is independent. The predicted branching ratios are (0.45–1.04) × 10-9 and (2.14–3.27) × 10-8 for B0 and Bs decay, respectively.