Quarks, diquarks, tetraquarks, and pentaquarks
Abstract:A particle about 50% more massive than a proton, with positive charge, positive strangeness and positive baryon number, has been claimed in several experiments. Such a particle cannot be made from three quarks; its minimal configuration requires four quarks and an antiquark and it became known as a ‘pentaquark'. This article summarizes the evidence and concentrates on the theoretical interest that it has excited into the nature of correlations among quarks and antiquarks in the strong interaction limit of QCD.
Document Type: Research Article
Affiliations: Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Keble Road, Oxford, OX1 3NP, UK
Publication date: March 1, 2006