Quark Energy Loss and Shadowing in Nuclear Drell–Yan Process

Abstract

The energy loss effect in nuclear matter is another nuclear effect apart from the nuclear effects on the parton distribution as in deep inelastic scattering process. The quark energy loss can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of three kinds of quark energy loss parameterizations given in literature and the nuclear parton distribution extracted only with lepton-nucleus deep inelastic scattering experimental data, measured Drell-Yan production cross sections are analyzed for 800GeV proton incident on a variety of nuclear targets from FNAL E866. It is shown that our results with considering the energy loss effect are much different from these of the FNAL E866 who analysis the experimental data with the nuclear parton distribution functions obtained by using the deep inelastic lA collisions and pA nuclear Drell-Yan data . Considering the existence of energy loss effect in Drell-Yan lepton pairs production,we suggest that the extraction of nuclear parton distribution functions should not include Drell-Yan experimental data.

Nuclear Dependence of Proton-Induced Drell-Yan Dimuon Production at 120 GeV at Seaquest

“…The K factor has been found to be generally of the form K = exp[(α s /2π)(4π 2 /3)], and has been calculated in considerable detail [20] to order O(α 2 s ) and are considered to be under control. Most importantly, it was found at the E-866 experiment that the differential cross section ratios in the next-to-leading order are almost identical to those in the leading order nuclear dependence (at 800 GeV) [21]. Further, similar results are given for the lower energy proton bombarding deuterium and tungsten at the Fermilab Main Injector (FMI, 120 GeV proton beam) [22] which is used at SeaQuest.…”

Measurement of Quark Energy Loss in Cold Nuclear Matter at Fermilab E906/SeaQuest

“…With greater energy-loss or lower beam proton energy E p , the suppression would be more significant. Although the derivation above is based on the leading-order Drell-Yan cross section, the behavior of the cross-section ratio observed still holds with high-order corrections since the overall K-factors are expected to simply cancel [53,54]. Indeed, a fair amount of approximation was employed in the previous discussion and at least a more-careful treatment on the PDFs are required for a quantitative analysis.…”

“…This hadronization process is not well understood yet but if it starts inside the medium, the interaction of the prehadron with the medium can contribute to the hadron suppression observed [50][51][52] and thus obscure the partonenergy-loss extraction. On the other hand, this ambiguity is absent in the Drell-Yan process, which has been regarded as the ideal tool for measuring parton energy loss in cold nuclear matter [53,54]. In the following, the Drell-Yan process and its unique role in energy-loss measurements will be discussed in detail, and the advantages of conducting such measurements in E906/SeaQuest experiment will be explained.…”

“…This result, however, is inconclusive [53,94,95] owing to the fact that the EKS98 analysis included E772 data [77] for determining the sea-quark shadowing without taking parton energy loss into account. Utilizing EKS98 for the shadowing correction could naturally lead to a smaller energy loss, compared to that if a different nPDF set were employed, as suggested in [54].…”

Theoretical analysis of double-differential cross sections of proton, deuteron, and triton emission in the p+Li7 reaction at 14 MeV

“…Therefore, the detailed study on p+ 7 Li reaction will extend the knowledge of light charged particle induced nuclear reactions with 1p-shell light nuclei involved, as well as the accurate structural information of some unstable light nuclei. Furthermore, this study will provide abundant proofs to test the reliability of statistical theory of light nucleus reactions (STLN), which has been applied successfully to calculate the double differential cross sections of outgoing neutrons both for neutron and proton induced nuclear reactions with 1p-shell light nuclei involved [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”