From the Flavour Symmetry to the Leptonic String

In any process of $\beta$-decay originates the birth of a dilepton by the same reason. Such a reason can, for example, be existence in all leptonic families of a unified flavour symmetrical force between the two left (right)-handed fermions of each type. It establishes those connections, at which there exist the left (right)-handed leptons in difermions comparatively for a long time without converting into the right (left)-handed ones, although this is not forbidden. In other words, a flavour symmetrical force relates the two left (right)-handed leptons in flavourless dileptons. They are conserved in the form of leptonic strings until an external action is able to separate their by parts in the particle type dependence. Therefore, a single or a double $\beta$-decay is carried out in nuclei without neutrinos as well as without electrons. In direct experiments, left (right)-handed dileptons are observed instead of electrons. Thus, all properties of electrons fixed in single or double $\beta$-decay one must consider as the characteristic features which refer doubtless only to a leptonic string uniting the electron and its antineutrino.