By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter i...By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model, a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/ψ production differential cross section ratios RFe/Be（XF）. It is shown that the energy loss effect of beam proton on RFe/Be（XF） is more important than the nuclear effects on parton distribution functions in the high Feynman variable XF region. It is found that the J/ψ-nucleon inelastic cross section depends on the Feynman variable xF and increases linearly with XF in the region XF 〉 0.2.展开更多
J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for...J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for J/ψproduction cross-section ratios RW/Be（x F） are presented and compared with the selected E866 experimental data with the cc remaining colored on its entire path in the medium. It is shown that the combination of the different nuclear effects accounts quite well for the observed J/ψ suppression in the experimental data. It is found that the J/ψ suppression on RW/Be（x F） from the initial state nuclear effects is more important than that induced by the energy loss of color octet cc in the large x F region. Whether the cc pair energy loss is linear or quadratic with the path length is not determined. The obtained cc pair energy loss per unit path length α = 2.78±0.81 Ge V/fm, which indicates that the heavy quark in cold nuclear matter can lose more energy compared to the outgoing light quark.展开更多
基金Supported by National Natural Science Foundation of China (11075044)Natural Science Foundation of Hebei Province(A2008000137)
文摘By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model, a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/ψ production differential cross section ratios RFe/Be（XF）. It is shown that the energy loss effect of beam proton on RFe/Be（XF） is more important than the nuclear effects on parton distribution functions in the high Feynman variable XF region. It is found that the J/ψ-nucleon inelastic cross section depends on the Feynman variable xF and increases linearly with XF in the region XF 〉 0.2.
基金Supported by National Natural Science Foundation of China(11075044,11347107)Natural Science Foundation of Hebei Province(A2013209299)
文摘J/ψ suppression in p-A collisions is studied by considering the nuclear effects on parton distribution,energy loss of beam proton and the finial state energy loss of color octet cc. The leading-order computations for J/ψproduction cross-section ratios RW/Be（x F） are presented and compared with the selected E866 experimental data with the cc remaining colored on its entire path in the medium. It is shown that the combination of the different nuclear effects accounts quite well for the observed J/ψ suppression in the experimental data. It is found that the J/ψ suppression on RW/Be（x F） from the initial state nuclear effects is more important than that induced by the energy loss of color octet cc in the large x F region. Whether the cc pair energy loss is linear or quadratic with the path length is not determined. The obtained cc pair energy loss per unit path length α = 2.78±0.81 Ge V/fm, which indicates that the heavy quark in cold nuclear matter can lose more energy compared to the outgoing light quark.
