Constraints on unparticle physics from solar and KamLAND neutrinos

Interest has been directed recently towards low energy implications of a non-trivial conformal sector of an effective field theory with an IR fixed point (ΛU), manifest in terms of “unparticles” with bizarre properties. We re-examine the implications of the limits on decay lifetimes of solar neutrinos for unparticle interactions. We study in detail the fundamental parameter space (ΛU,M) and derive bounds on the energy scale M characterizing the new physics. We work strictly within the framework where conformal invariance holds down to low energies. We first assume that couplings of the unparticle sector to the Higgs field are suppressed and derive bounds with ΛU in the TeV region from neutrino decay into scalar unparticles. These bounds are significant for values of the anomalous dimension of the unparticle operator 1.0