Lepton Polarization Asymmetry in B→ K⁽*⁾ l+l-

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We investigate the longitudinal lepton polarization asymmetry in the exclusive processes B→ K l+l- and B→ K* l+l-. We include both short and long-distance contributions to the asymmetry in our discussions. We find that average values of the polarization asymmetries of the muon and tau for B→ K⁽*⁾μ+μ- and B→ K⁽*⁾τ+τ- are -0.8(-0.7) and -0.2(-0.5), respectively.