Six-quark clusters and neutrinoless double β-decay

The neutrinoless double β-decay mediated by heavy Majorana neutrinos or Higgs particles is studied in the presence of six-quark clusters in nuclei. The probability of finding such clusters in nuclei is estimated. The structure of the six-quark clusters, which may also be important for other short-range processes, is studied using group theoretical techniques in the group chain SU(24) contains SUsub(c)(3) x SUsub(x)(2) x SUsub(IS)(4). Explicit calculations are presented in the case of the experimentally interesting 48Ca -> 48Ti decay. (orig.)