Constraining τ-lepton dipole moments and gluon couplings at the LHC

We study the constraints that can be placed on anomalous τ-lepton couplings at the LHC. We use an effective Lagrangian description for physics beyond the standard model which contains the τ-lepton anomalous magnetic moment, electric dipole moment, and weak dipole moments in two operators of dimension 6. We include in our study two additional operators of dimension 8 that directly couple the τ leptons to gluons and are therefore enhanced at the LHC. We consider the two main effects from these couplings: modifications to the Drell-Yan cross section and to the τ-lepton pair production in association with a Higgs boson. We find that a measurement of the former at the 14% level can produce constraints comparable to existing ones for the anomalous dipole couplings and that a bound on the latter at a sensitivity level of 500 σ_SM or better would produce the best constraint on the τ-gluonic couplings.