Charmonium dissociation cross sections and p– A collisions

• Published in: Nuclear physics. A 2003-01, Vol.713 (3), p.470-497
• Main Authors: Xu, X.-M., Shen, W.Q., Feng, Y.C., Zhou, D.C.
• Format: Article
• Language: English
• Subjects: Charmonium dissociation cross sections; J/ ψ, ψ′ and χc suppressions; Proton–nucleus reactions
• ISSN: 0375-9474
• DOI: 10.1016/S0375-9474(02)01306-4

Charmonium dissociations by nucleons are first studied from a quark–quark potential in combination with quark exchange mechanism. Wave functions of nucleons and charmed baryons involved in dissociation reactions result from a fit to mass splittings of baryons with spins 1 2 and  3 2 . Transverse momentum and x F distributions of prompt J/ ψ produced in 800 GeV/ c p–Be collisions are calculated by using NRQCD dσ/d t ̂ for parton–parton scatterings and taking into account initial transverse-momentum distributions of partons inside nucleons. We emphasize that the new dissociation cross sections of J/ ψ, ψ′ and χ cJ give rise to remarkable differences of J/ ψ, ψ′ and χ c suppressions at large negative x F in p–W collisions at s NN =38.8 and 41.6 GeV and p–Au collisions at s NN =130  GeV .