A Review On Diquark Physics in QCD Phase Transition

The importance of diquarks has been noticed in the context of several elementary particle processes. In recent years the study of diquarks has become of considerable interest in highlighting its role in high density physics from the point of view of astrophysical situations and cosmological conditions. In the present paper an attempt is made to briefly review the role of diquarks in conventional physics and in Quantum Chromodynamic phase transition. The importance of equation of state for point-like scalar diquark (PSD) and extended scalar diquark (ESD) gas and matter is reviewed. In this regard, the sensitivity of ESD energy on the effective interaction parameter, within the frame work of \phi^4 theory, is studied. The role of diquarks in astro-physical situations and cosmological conditions with reference to the early phases of the origin of the universe is discussed. The recent discovery of \theta^+ (1540) baryon - a pentaquark, which may be considered as a two highly correlated ud-diquark pairs and an anti strange quark, is also highlighted.