We list all scalar and vector leptoquark states that contribute to the $b\to s{\ell }^{+}{\ell }^{-}$ effective Hamiltonian. There are altogether three scalar and four vector leptoquarks that are relevant. For contribution of each state we infer the correlations between effective operators and find that only two baryon number-violating vector leptoquarks give rise to scalar and pseudoscalar four-fermion operators, whereas the scalar states can contribute to those operators only when two states with same charge are present. We bound the resulting Wilson coefficients by imposing experimental constraints coming from branching fractions of $B\to K{\ell }^{+}{\ell }^{-}$, $B_s\to {\mu }^{+}{\mu }^{-}$, and $B\to X_s{\mu }^{+}{\mu }^{-}$ decays.

• Received 24 June 2012

DOI:https://doi.org/10.1103/PhysRevD.86.055004