We define and study hard "semi-exclusive" processes of the form A + B -> C + Y which are characterized by a large momentum transfer between the particles A and C and a large rapidity gap between the final state particle C and the inclusive system Y. Such reactions are in effect generalizations of deep inelastic lepton scattering, providing novel currents which probe specific quark distributions of the target B at fixed momentum fraction. We give explicit expressions for photo- and leptoproduction cross sections such as #gamma#p -> #pi#Y in terms of parton distributions in the proton and the pion distribution amplitude. Semi-exclusive processes provide opportunities to study fundamental issues in QCD, including odderon exchange and color transparency, and suggest new ways to measure spin-dependent parton distributions.
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机译：我们定义并研究形式为A + B-> C + Y的硬“半排他”过程，其特征是粒子A和C之间的动量传递大，最终状态粒子C和包含物之间的快速间隙大这种反应实际上是深层非弹性轻子散射的概括，提供了新颖的电流，可探测固定动量分数下目标B的特定夸克分布。对于质子中的parton分布和介子的分布振幅，我们给出了光生产和le生产横截面的明确表达式，例如＃gamma＃p->＃pi＃Y。半排他性过程提供了研究QCD中基本问题的机会，包括奇数交换和颜色透明性，并提出了测量自旋相关的单子分布的新方法。
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