Non-Standard Neutrino Interactions at Colliders

Abstract

Many extensions of the Standard Model lead to non-standard neutrino interactions (NSI), which can affect the interpretation of current and future neutrino data. We explore an alternative approach to the study of these dimension eight four fermion interactions (of coefficient $4 \epsilon G_F/\sqrt{2}$), by bringing into play collider data. In models where coefficients of potential dimension six operators are suppressed by cancellations, LEP2 provides interesting bounds on NSI operators ($\epsilon \lsim 10^{-2} - 10^{-3}$). If NSI are contact interactions at LHC energies, they induce an effective interaction $\bar{q} q W^+W^- e_\a^+ e_\b^-$(according to the Equivalence Theorem), to which the LHC at 14 TeV and with 100 fb$^{-1}$ of data has excellent sensitivity ($\epsilon \gsim 3 \times 10^{-3}$).