Abstract
We study the transverse lepton polarization (P T ) in the exclusive processes of B→Kℓ + ℓ - and B →K*ℓ + ℓ - . We find that the polarization is zero for B→Kℓ + ℓ - but nonzero for B→;K*ℓ + ℓ - . The average values of P T (B→K*ℓ + ℓ - ) are 8.4 × 10 -4 and 2.0 × 10 -2 for ℓ = μ and ℓ = τ, respectively. The polarization asymmetry is a T-odd observable, which connects with the non-Hermiticity of the effective Hamiltonian, arising mainly from the cc intermediate states. We also include the other two orthogonal components, longitudinal and normal polarizations, in our discussions.