  The planned rhenium beta-decay experiment MARE might probe the absolute mass
scale of neutrinos with the same sensitivity as the tritium beta-decay
experiment KATRIN, which will start data taking in 2011 and will proceed for
five years. We present the energy distribution of emitted electrons for the
first unique forbidden beta-decay of 187Re. It is found that the p-wave
emission of electron dominates over the s-wave. By assuming mixing of three
neutrinos the Kurie function for the rhenium beta-decay is derived. It is shown
that the Kurie plot near the endpoint is within a good accuracy linear in the
limit of massless neutrinos like the Kurie plot of the superallowed beta-decay
of 3H.

High Energy Physics - Phenomenology;Nuclear Theory