Comparison of the contribution of the photon's vector and scalar Kaluza-Klein partners in the neutron lifetime

A discrete extra dimension of size 11.8 fm would imply the existence of vector X and scalar H bosons as photon's Kaluza-Klein partners. The massive vector X can be identified with the particle X17 suggested by ATOMKI's experiment. The particle model of extended photon sector coupled to extended nucleon, electron and neutrino also implies the neutron decay to its Kaluza-Klein partner. There are several different channels triggered by X and H. In this paper ve compare the contribution from them and imply some physical consequences on the parameters of the model. (paper)