Probing physics beyond the standard model with neutrinoless double beta decay

Neutrinoless double beta decay (0 nu beta beta) is the most sensitive low-energy probe for physics beyond the standard model. Usually the lower limit of 0 nu beta beta decay half-lives is interpreted in terms of an upper limit on the effective Majorana neutrino mass. However, numerous further possible extensions of the standard model can be tested by 0 nu beta beta decay. Among the models which can contribute to 0 nu beta beta decay are left-right symmetric models of the weak interaction, R-parity violating supersymmetric theories and models of Light leptoquarks. We review the constraints on these models which can be derived currently from the non-observation of 0 nu beta beta decay and discuss the impacts of these results on accelerator searches and other experiments. Interestingly, it is found that 0 nu beta beta decay probes already now the TeV scale on which new physics should manifest itself according to present theoretical expectations.