XIAMEN UNIV,DEPT PHYS,XIAMEN 361005,PEOPLES R CHINA
; GUANGXI UNIV,DEPT PHYS,NANNING 530004,PEOPLES R CHINA
; ACAD SINICA,SHANGHAI INST NUCL RES,SHANGHAI 201800,PEOPLES R CHINA
; ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA
A method of using the Bardeen-Cooper-Schrieffer (BCS) nuclear wave function to treat the two-nucleon mechanism for neutrinoless double beta decay process 0+ --> 0+ is proposed. The neutrinoless decay mode and the neutrinoless decay accompanied by a Majoron emission mode of Se-82 are studied. Our calculated results show that to reproduce the experimental value of tau(0nu) > 1.8 X 10(22) yr for neutrinoless double beta decay of Se-82, the Majorana neutrino mass m(nu) < 6.2 eV and the mixing parameter of right-handed current eta < 7.0 x 10(-6) In the emission with a Majoron mode the effective Majoron coupling to neutrino is deduced from the experimental value of tau(0nu,H) > 4.4 x 10(20) yr for Se-82 with the result (g(H0)) < 6.2 x 10(-4).