Following recent low-threshold analysis of the Sudbury Neutrino Observatory
and asymmetry measurements of the BOREXINO Collaboration of the solar neutrino
flux, we revisit the analysis of the matter effects in the Sun. We show that
solar neutrino data constrains the mixing angle θ13 poorly and that
subdominant Standard Model effects can mimic the effects of the physics beyond
the Standard Model.Comment: 12 pages of LATEX, 8 figure