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1.
By means of two typical kinds of quark energy loss parametrization and the nuclear parton distribu-tions determined only with lepton-nuclear deep inelastic scattering experimental data, a leading order analysis is performed on the proton-induced Drell-Yau differential cross section ratios of tungsten versus deuterium as a function of the quark momentum fraction in the beam proton and target nuclei. It is found that the theoretical results with quark energy loss are in good agreement with the experimental data. The quark energy loss effect produces approximately 3% to 11% suppression on the Drell-Yan differential cross section ratios RW/D in the range 0.05 ≤ x2≤ 0.3. The application of nuclear Drell-Yan data with heavy targets is remarkably subject to difficulty in the constraint of the nuclear sea quark distribution. 相似文献
2.
电沉积法制备介孔TiO_2/CdS薄膜光电极 总被引:2,自引:0,他引:2
采用阴极恒电位沉积法,在介孔TiO2薄膜上制备了介孔TiO2/CdS薄膜光电极,用XRD,SEM,Raman,SPS和UV-Vis等多种手段对薄膜电极进行了表征.结果表明,CdS成功沉积到介孔TiO2的表面和孔道内,形成了异质结结构.通过光电流作用谱考察了该复合体薄膜电极的光电性能,结果表明,与单纯的介孔TiO2薄膜相比,其光电转换效率显著提高,这是由于CdS具有吸收可见光的特性以及CdS与介孔TiO2形成异质结从而使得光生载流子更容易分离的结果. 相似文献
3.
二茂铁(Ⅲ)鎓离子三氯乙酸盐对艾氏腹水癌细胞DNA合成的抑制郭茂林,杨频,赵春贵,杨斌盛,杨维萍(山西大学分子科学研究所,太原,030006)(山西煤炭中心医院肿瘤科)关键词二茂铁离子盐,抗癌剂,DNA金属茂类化合物抗癌活性及作用机理的研究是近年来比... 相似文献
4.
DUANChun-Gui CUIShu-Wen YANZhan-Yuan 《理论物理通讯》2005,44(1):123-127
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 Dre11-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 Dre11-Yan production cross sections are analyzed for 800 GeV 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 those of the FNAL E866, who analyzes the experimental data with the nuclear parton distribution functions obtained by using the deep inelastic IA 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 shoul““““d not include Dre11-Yan experimental data. 相似文献
5.
Nuclear Effects in Structure Functions xFa(x, Q^2) from Charge Current Neutrino Deep Inelastic Scattering 下载免费PDF全文
By taking advantage of the model-independent nuclear parton distributions, the structure functions xF3(x, Q^2) are calculated, in comparison with the experimental data from CCFR neutrino-nuclei charge current deep inelastic scattering. It is shown that shadowing and anti-shadowing effects occur in valence quark distributions for small and medium x regions, respectively. It is suggested that the neutrino experimental data should be employed in the future for pinning down the nuclear patton distributions. 相似文献
6.
The extended x-rescaling model can explain the quark's nuclear effect very well. Weather it can also explain the gluon's nuclear effect should be investigated further. Associated J/ψ and γ production with large
PT is a very clean channel to probe the gluon distribution in proton or nucleus. In this paper, using the extended x-rescaling model,
the PT distribution of the nuclear effect factors
of p+Fe→J/ψ+γ+X process is calculated and discussed. Comparing our theoretical results with the future
experimental data, the extended x-rescaling model can be
examined. 相似文献
7.
YANZhan-Yuan LIZhi-Wen DUANChun-Gui 《理论物理通讯》2004,42(3):389-393
We present a study of associated ηc and γ double diffractive production in pp^- collision based on Ingelman-Schlein model, and the framework of non-relativistic QOD factorization formalism for quarkonia production. The prediction of ηc and γ is more reliable than J/ψ production, because the associated ηc and γ production is a pure color-octet process, and the dominant contribution comes from color octet ^1S0^(8) subprocess, which is related to the color octet matrix element of ^1S0(8) of J/ψ by the heavy quark spin symmetry and the large PT J/ψ production data. We find that the ratio of diffractive to inclusive cross sections is independent of the values of color octet matrix elements, but is sensitive to the gluon factor of the Pomeron and renormalized Pomeron flux factors. So experimental measurement of this ratio can give us more information of the nature of Pomeron and test the assumption of hard diffractive factorization in hadron-hadron collisions. 相似文献
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9.
Starting from the point-view that the constituent quark has its own inner structure and according to the hypothesis of the maximum non-perturbative strong interaction reaction which should be obeyed in high energy strong-soft Processes ,we proposed a structure model of the Reggeon(R). In such processes a pair of constituent quark-antiquark in colliding hadrons would individually desociate with certain probahility into a non-perturbative gluon and a spinor-like cluster firstly. The spinor-like clusters will further emit non-perturbative gluons and then annihilate each other. Corresponding to such mechanism the relevant structure of R in the field theory can be represented by summing over a set of cutting ladder diagrams, where the vertical lines are the propagators of spinor-like clusters and the rungs are non-perturbative gluons. In the multi-Regge region where the energy of the system is very large and its momentum transfer│t│is very small, under the approximation that only the leading order logarithm terms of s are preserved, the scattering amplitudes for these cutting ladder diagrams are derived and summed. Thus, a compact formula of the typical Regge pole trajectory of mesons which are composed of light quarks is obtained. 相似文献
10.
We study pion-proton (πp) Drell-Yan (DY) dilepton production
in the target rest frame with color dipole model. The prediction
for πp DY cross section at the energies of RHIC and LHC
is presented, and it can be compared with the data directly, because it
does not need K factor. At the same time, the transverse momentum
distribution is shown in quantities, which is not available from
the standard parton model. The experimental studies of the process
could test the color model for DY dilepton production. 相似文献