Pentaquarks uudds with one color sextet diquark.
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.
Semay
Claude
C
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
Brau
Fabian
F
Silvestre-Brac
Bernard
B