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 s tandard equilibrium thermal-energy distribution. We are able to derive stro ng constraints on such deviations by using the detailed helioseismic inform ation of the solar structure. If a small deviation is parameterized with a factor exp{- delta(E/kT)(2)}, we find that delta should lie between -0.005 and +0.002. However, even values of delta as small as 0.003 would still giv e important effects on the neutrino fluxes. (C) 1998 Published by Elsevier Science B.V. All rights reserved.