出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati

摘要：We study three quark systems in Maximally Abelian (MA) and Maximal Center (MC) projected
QCD on quenched SU(3) lattice, and also in the monopole/photon part, where only the colorelectric/
magnetic current exists, using the Hodge decomposition. First, we perform the quantitative
study of the three-quark (3Q) potential V3Q and the string tension s3Q in baryons. For
MA projected QCD, the monopole part and MC projected QCD, we find that the confinement
potential in V3Q obeys the Y-Ansatz and the string tension s3Q is approximately equal to that in
SU(3) QCD. The universality of the string tension, s3Q 'sQ¯Q, is also found between the 3Q and
the Q¯Q potentials. We find a strong similarity of the inter-quark potential between the monopole
part and MC projected QCD. In contrast, almost no confinement force is found in the inter-quark
potential in the photon part. Next, we study the spectrum of light hadrons in MA projected QCD
and the monopole/photon part, paying attention to the N-D mass splitting. We find that the N-D
mass splitting is significantly reduced in MA projected QCD and the monopole part, where the
one-gluon-exchange effect or the Coulomb-potential part is largely reduced due to the Abelianization
or the Hodge decomposition. This fact seems to indicate that the main origin of the mass
splitting is one-gluon exchange.