Constraints on additional Z bosons derived from neutrino-electron scattering measurements

Abstract

We report new constraints on the existence of additional Z bosons derived from neutrino{electron scattering data. The analysis is based on data taken by the CHARM II Collaboration during ve y ears of exposure of the detector to the wide band neutrino beam at CERN. The limits on the mass of these new particles are evaluated in the framework of E 6 superstring-inspired theories and Left-Right symmetric models. Limits on the so-called Z 1 are also reported.

Tests of flavor universality for neutrino-Zcouplings in future neutrino experiments

“…CHARM II Collaboration obtained data on ν µ e → ν µ e scattering. These data together with LEP results place the limit [2,3] |∆ µ | ≤ 0.037.…”

“…In Fig. 4 we also show the limit (area bounded by dotted lines) obtained from inequality (3). We see from this figure that limit obtained from the CHARM II data is approximately 6 times weaker than our limits.…”

The phenomenology of extra neutral gauge bosons

“…See references [6,7] for a review and references to older experiments. Recent results of neutrino scattering experiments can be found in references [257,258], a recent review is given in reference [259].…”

“…As e + e − collisions at the Z 1 peak, the agreement of these measurements with the SM prediction constrains physics beyond the SM. The constraints on extra neutral gauge bosons obtained by the CHARM II Collaboration [258] are given in table 4.3. Comparisons of the excluded ranges in the θ M − M Z ′ plane with L3 measurements can be found in figure 46 of reference [259].…”