Helioseismology can test the Maxwell-Boltzmann distribution

Nuclear reactions in stars occur between nuclei in the high-energy tail of the energy distribution and are sensitive to possible deviations from the standard equilibrium thermal-energy distribution. We are able to derive strong constraints on such deviations by using the detailed helioseismic information of the solar structure. If a small deviation is parameterized with a factor exp{−δ(E/kT)2}, we find that δ should lie between −0.005 and +0.002. However, even values of δ as small as 0.003 would still give important effects on the neutrino fluxes.