On the CP violation associated with Majorana neutrinos and neutrinoless double-beta decay

Assuming 3-upsilon mixing and massive Majorana neutrinos, we analyze the possibility of establishing the existence of CP violation associated with Majorana neutrinos in the lepton sector by (i) measuring of the effective Majorana mass 1(m)l in neutrinoless double beta decay with a sufficient precision and (ii) by measuring of, or obtaining a stringent upper limit on, the lightest neutrino mass m(1). Information on m(1) can be obtained in the H-3 beta-decay experiment KATRIN and from astrophysical and cosmological observations. Proving that the indicated CP violation takes place requires, in particular, a relative experimental error on the measured value of I (m) I not bigger than 20%, a theoretical uncertainty in the value of I (m) I due to an imprecise knowledge of the corresponding nuclear matrix elements smaller than a factor of 2, a value of tan(2) theta(circle dot) greater than or similar to 0.55, and values of the relevant Majorana CP-violating phases typically within the intervals of similar to(pi/2-3pi/4) and similar to (5pi/4-3pi/2). In the case of, e.g.,quasi-degenerate neutrino mass spectrum it requires also that the neutrino masses have values not smaller than similar to 0.7 eV. (C) 2002 Elsevier Science B.V. All rights reserved.