We discuss the problem of solar hep neutrinos originating from the reaction p
+ 3He -> 4He + e+ + nu and obtain a relation between the astrophysical S-factor
of the hep process and the cross section of the process e- + 4He -> 3H + n + nu
near threshold. The relation is based on the isotopic invariance of strong
interactions.
The measurement of the latter cross section would allow to obtain
experimental information on S(hep), the value of which, at the moment, is known
only from theoretical calculations.Comment: 10 pages, no figure
