title: Pentaquarks uudds with one color sextet diquark.
abstract: The masses of pentaquarks uudds are calculated within the framework of a semirelativistic effective QCD Hamiltonian using a diquark picture. This approximation allows a correct treatment of the confinement, assumed here to be similar to a Y junction. With only color antitriplet diquarks, the mass of the pentaquark candidate Theta with positive parity is found around 2.2 GeV. It is shown that, if a color sextet diquark is present, the lowest uudds pentaquark is characterized by a much smaller mass with a negative parity. A mass below 1.7 GeV is computed if the masses of the color antitriplet and color sextet diquarks are taken similar.
authors.affiliation: Groupe de Physique Nucléaire Théorique, Université de Mons-Hainaut, Académie Universitaire Wallonie-Bruxelles, Place du Parc 20, B-7000 Mons, Belgium. claude.semay@umh.ac.be
authors.forename: Claude
authors.initials: C
authors.lastname: Semay
authors.forename: Fabian
authors.initials: F
authors.lastname: Brau
authors.forename: Bernard
authors.initials: B
authors.lastname: Silvestre-Brac