On the structure of the observable algebra of QCD on the lattice

The structure of the observable algebra of lattice QCD in the Hamiltonian approach is investigated. As was shown earlier, is isomorphic to the tensor product of a gluonic C*-subalgebra, built from gauge fields and a hadronic subalgebra constructed from gauge-invariant combinations of quark fields. The gluonic component is isomorphic to a standard CCR algebra over the group manifold SU(3). The structure of the hadronic part, as presented in terms of a number of generators and relations, is studied in detail. It is shown that its irreducible representations are classified by triality. Using this, it is proved that the hadronic algebra is isomorphic to the commutant of the triality operator in the enveloping algebra of the Lie superalgebra sl(1/n) (factorized by a certain ideal). © 2005 IOP Publishing Ltd.