Constraints from solar and reactor neutrinos on unparticle long-range forces

Abstract

We have investigated the impact of long-range forces induced by unparticle operators ofscalar, vector and tensor nature coupled to fermions in the interpretationof solar neutrinos and KamLAND data. If the unparticle couplings to theneutrinos are mildly non-universal, such long-range forces will not factorize outin the neutrino flavour evolution. As a consequence large deviations from theobserved standard matter-induced oscillation pattern for solar neutrinos would begenerated. In this case, severe limits can be set on the infrared fixed point scale,Λu, and the new physicsscale, M, as a functionof the ultraviolet (dUV) and anomalous (d) dimension of the unparticle operator. For a scalar unparticle, for instance, assuming thenon-universality of the lepton couplings to unparticles to be of the order of a few per mil we find that,for dUV = 3 and d = 1.1, M is constrained to be TeV ( TeV) if Λu = 1 TeV (10 TeV).For given values of Λu and d, the correspondingbounds on M for vector(tensor) unparticles are ∼100 () times those for the scalar case. Conversely, these results can be translated into severeconstraints on universality violation of the fermion couplings to unparticle operators withscales which can be accessible at future colliders.