Paper detail

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 six. We include in our study two additional operators of dimension eight 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.