Testing for new physics with low-energy anti-neutrino sources: LAMA as a case study

Some electroweak models with extended neutral currents, such as those based on the E-6 group, lead to an increase of the <(nu)over bar> - e scattering cross section at energies below 100 keV. We propose to search for the heav y Z' boson contribution in an experiment with a high-activity artificial ne utrino source and with a large-mass detector. We present the case for the L AMA experiment with a large NaI(Tl) detector located at the Gran Sasso unde rground laboratory. The neutrino flux is known to within a one percent accu racy, in contrast to the reactor case and one can reach lower neutrino ener gies. Both features make our proposed experiment more sensitive to extended gauge models, such as the chi model. For a low enough background the sensi tivity to the Z(chi) boson mass would reach 600 GeV for one year running of the experiment. (C) 1999 Elsevier Science B.V.