pentaquarks

Noun

pentaquark (plural pentaquarks)

1. (particle) Any of a class of subatomic particles (previously hypothetical, since detected, subject to confirmation) consisting of a group of five quarks (compared to three quarks in normal baryons and two in mesons), or more specifically four quarks and one antiquark (symbol Θ).
   • Evidence for and against the heavier pentaquark states, the #92;Xi(1862) and the #92;Theta⁰#95;c(3100) observed at CERN and at HERA, respectively, are also discussed. I conclude that the evidence against the latter two heavier pentaquark baryons is rapidly increasing making their existence highly...2006, Volker D. Burkert, “Have Pentaquark States Been Seen?”, in Richard Brenner, Carlos P. De Los Heros, Johan Rathsman, editors, Lepton and Photon Interactions at High Energies: Proceedings of the...