Study of electron-neutrino—electron elastic scattering at LAMPF

Neutrino-electron elastic scattering was observed with a 15-ton fine-grained tracking calorimeter exposed to electron neutrinos from muon decay at rest. The measured ${\nu }_e{e}^{-}\to {\nu }_e{e}^{-}$ elastic scattering rate of 236±35 events yields the total elastic scattering cross section $10.0\pm 1.5\left(\mathrm{stat}\right)\pm 0.9\left(\mathrm{syst}\right)\times {10}^{-45\mathrm{}} \mathrm{c}{\mathrm{m}}^2\times \left[E_{\nu } \right(\mathrm{MeV}\left)\right]$, and a model-independent measurement of the strength of the destructive interference between the charged and neutral currents, $I=-1.07\mathrm{}\pm 0.21$, that agrees well with the standard model (SM) prediction $I=-1.08\mathrm{}$. The agreement between the measured electroweak parameters and SM expectations is used to place limits on neutrino properties, such as neutrino flavor-changing neutral currents and neutrino electromagnetic moments. Limits are placed on the masses of new bosons that interact with leptons: for a neutral tensor boson, $M_T>105\mathrm{}$ GeV; for a neutral (pseudo)scalar boson, $M_{P,S}>47\mathrm{}$ GeV; for a charged Higgs boson, $M_{{\chi }^{+}}>87\mathrm{}$ GeV; and for a purely left-handed charged (neutral) vector boson, $M_x>239\mathrm{} \mathrm{}\left(119\right)\mathrm{}$ GeV.