The crucial role of a Lorentz scalar Lagrangian density whos e dimension is [ L − 4 ] ( ~ = c = 1) in a construction of a quantum theory is explained. It turn s out that quan- tum functions used in this kind of Lagrangian density have a d efinite dimension. It is explained why quantum functions that have the dimension [ L − 1 ] cannot describe parti- cles that carry electric charge. It is shown that the 4-curre nt of a quantum particle should satisfy further requirements. It follows that the pion and t he W ± must be composite par- ticles. This outcome is inconsistent with the electroweak t heory. It is also argued that the 125 GeV particle found recently by two LHC collaborations is not a Hi ggs boson but a t ̄ t meson.