Beta decay of the free neutron and hypothesis of intermediate leptoquark bosons

The possibility of the production of virtual leptoquark intermediate bosons in the beta decay of the free neutron has been investigated. It has been s hown that, in this process, the channel associated with beta transitions in the right-handed nucleon current can be interpreted in terms of such a mec hanism involving scalar leptoquark color bosons with an electric charge of -2/3 and leptoquark multiplets including the left-handed leptons. The possi bility of extending this hypothesis by means of the additional assumption t hat there exists a similar mechanism featuring a leptoquark multiplet inclu ding the left-handed u quarks and the right-handed neutrino has been consid ered. It has been shown that, in this case, additional terms that are equiv alent to exotic scalar (pseudoscalar) and tensor versions of weak interacti on arise in the effective lepton-hadron Hamiltonian of weak interaction. Th e existence of such terms does not contradict modern experimental data, and their relative contribution to the general process is expected to be about 0.5% of the contribution from the standard decay mechanism. A precision me asurement of electron-neutrino correlations in neutron decay or in allowed nuclear beta transitions would be a crucial test for the above extended hyp othesis.