Contributions of leptoquark interactions into the tensor and scalar form   factors of K to pi l nu_l decay
  In the framework of scalar-vector dominance we calculate the hadronic matrix elements of scalar and tensor effective quark currents induced by virtual leptoquark interactions. Combined bounds on the product of couplings and leptoquark masses are obtained from experimental data. 
V.V. Kiselev, A.K. Likhoded, V.F. Obraztsov