Constraints on two-lepton two-quark operators
IPNL, Université Lyon 1, Université de Lyon, CNRS/IN2P3, 4 rue E. Fermi, 69622, Villeurbanne cedex, France
Revised: 3 September 2010
Published online: 19 November 2010
Physics from beyond the Standard Model, such as leptoquarks, can induce four fermion operators involving a quark, an anti-quark, a lepton and an anti-lepton. We update the (flavour-dependent) constraints on the coefficients of such interactions, arising from collider searches for contact interactions, meson decays and other rare processes. We then make naive estimates for the magnitude of the coefficients, as could arise in texture models or from inverse hierarchies in the kinetic term coefficients. These “expectations” suggest that rare kaon decays could be a good place to look for such operators.
© Springer-Verlag / Società Italiana di Fisica, 2010