Improved limit on electron neutrino charge radius through a new evaluation of the weak mixing angle

We have obtained a new limit on the electron neutrino effective charge radius from a new evaluation of the weak mixing angle by a combined fit of all electron(anti)neutrino electron elastic scattering measurements. Weak mixing angle is found to be sin θW = 0.259±0.025 in the low energy regime below 100 MeV. The electron neutrino charge radius squared is bounded to be in the range −0.13× 10 cm < 〈r2 νe〉 < 3.32 × 10 cm at 90% C.L. Both results improve previously published analyses. We also discuss perspectives of future experiments to improve these constraints.