  New limits on the weak mixing angle and on the electron neutrino effective
charge radius in the low energy regime, below 100 MeV, are obtained from a
combined fit of all electron-(anti)neutrino electron elastic scattering
measurements. We have included the recent TEXONO measurement with a CsI (Tl)
detector. Only statistical error of this measurement has been taken into
account. Weak mixing angle is found to be sin^2 theta_W = 0.255 +0.022 -0.023.
The electron neutrino effective charge radius squared is bounded to be r^2 =
(0.9 +0.9 -1.0) x 10^{-32} cm^2. The sensitivity of future low energy neutrino
experiments to nonstandard interactions of neutrinos with quarks is also
discussed.
