Spectroscopic studies of neutrinoless double beta decays $\left(0\mathrm{}\nu \beta \beta \right)$ from ${}^{100}\mathrm{Mo}$ were made by means of ELEGANT V. The most stringent limits on the $0\nu \beta \beta$ half-lives were obtained for the ground state transitions $T_{1/2}^{0\nu }{(m}_{\nu })>\mathrm{}5.5\mathrm{}(10.3)\mathrm{}\times {10}^{22},$ $T_{1/2}^{0\nu }\left(\lambda \right)>\mathrm{}4.2\mathrm{}\left(8.5\right)\mathrm{}\times {10}^{22},$ and $T_{1/2}^{0\nu }\left(\eta \right)>\mathrm{}4.9\mathrm{}\left(9.3\right)\mathrm{}\times {10}^{22}\hspace{0.5em}\mathrm{yr},$ with 90(68)% C.L., for the mass term $〈m_{\nu }〉$ and for the right-handed weak current terms of $〈\lambda 〉$ and $〈\eta 〉,$ respectively. Using the nuclear matrix elements of the QRPA calculation by Tomoda et al., these limits lead to upper limits of $〈m_{\nu }〉<2.1\mathrm{}\left(1.5\right)\mathrm{}\hspace{0.5em}\mathrm{eV},$ $〈\lambda 〉<3.2\mathrm{}\left(2.5\right)\mathrm{}\times {10}^{-6},$ and $〈\eta 〉<2.4\mathrm{}\left(1.9\right)\mathrm{}\times {10}^{-8}$ with 90(68)% C.L. Limits on other terms beyond the standard theory are also discussed.

• Received 27 November 2000

DOI:https://doi.org/10.1103/PhysRevC.63.065501