Novel Method for the Direct Measurement of the τ Lepton Dipole Moments.

A novel method for the direct measurement of the elusive magnetic and electric dipole moments of the τ lepton is presented. The experimental approach relies on the production of τ^{+} leptons from D_{s}^{+}→τ^{+}ν_{τ} decays, originating in fixed-target collisions at the LHC. A sample of polarized τ^{+} leptons is kinematically selected and subsequently channeled in a bent crystal. The magnetic and electric dipole moments of the τ^{+} lepton are measured by determining the rotation of the spin-polarization vector induced by the intense electromagnetic field between crystal atomic planes. The experimental technique is discussed along with the expected sensitivities.