MSW nu(3)->nu(s) transition solution of the solar neutrino problem

We study the stability of the two-neutrino MSW solution of the solar neutrino problem, corresponding to solar nu(e) transitions into a sterile neutrino, nu(e) --> nu(s), with respect to changes of the total fluxes of B-8 and Be-7 neutrinos, Phi(B) and Phi(Be). For any value of Phi(Be) from the interval 0.7 Phi(Be)(BP) less than or equal to Phi(Be) less than or equal to 1.3 Phi(Be)(BP) the nu(e) --> nu(s) MSW transitions provide at 95% C.L. a description of the existing solar neutrino data for 0.40 Phi(B)(BP) less than or similar to Phi(B) less than or similar to 36 Phi(B)(BP) Phi(B)(BP) and Phi(Be)(BP) being the fluxes in the solar model of Bahcall and Pinsonneault [Rev. Mod. Phys. 69, 85 (1992)]. The corresponding allowed regions of values of the parameters Delta m(2) and sin(2)2 theta, characterizing the solar neutrino transitions, are derived. The physical implications of the found MSW nu(e) --> nu(s) solutions for the future solar neutrino experiments are considered as well.