Minakata H author Pena-Garay C author 2012 English We discuss constraints on the coefficient A(MSW) which is introduced to simulate the effect of weaker or stronger matter potential for electron neutrinos with the current and future solar neutrino data. The currently available solar neutrino data leads to a bound A(MSW) = 1.47(+0.54)(-0.42)((-0.82)(+1.88)) at 1 sigma (3 sigma) CL, which is consistent with the Standard Model prediction A(MSW) = 1. For weaker matter potential (A(MSW) < 1), the constraint which comes from the flat B-8 neutrino spectrum is already very tight, indicating the evidence for matter effects. However for stronger matter potential (A(MSW) > 1), the bound is milder and is dominated by the day-night asymmetry of B-8 neutrino flux recently observed by Super-Kamiokande. Among the list of observables of ongoing and future solar neutrino experiments, we find that (1) an improved precision of the day-night asymmetry of B-8 neutrinos, (2) precision measurements of the low-energy quasi-monoenergetic neutrinos, and (3) the detection of the upturn of the B-8 neutrino spectrum at low energies are the best choices to improve the bound on A(MSW). WOS:000311152600001 exported from refbase (https://references.ific.uv.es/refbase/show.php?record=1234), last updated on Thu, 10 Jan 2013 16:05:00 +0000 text http://arxiv.org/abs/1009.4869 http://arxiv.org/abs/1009.4869 10.1155/2012/349686 Minakata+Pena-Garay2012 2012 Hindawi Publishing Corporation continuing periodical academic journal 2012 349686 - 15pp 1687-7357