标题： HERA中J/psi介子的产生 显示英文标题

标题： Production of J/psi Mesons at HERA

摘要： 非弹性及衍射产生J/psi介子在HERA的综述。 非弹性光生数据在下一阶精度的色单态模型中误差范围内描述良好。 在相空间的许多区域进行了NRQCD/因子化方法预测的色八重态过程的搜索。 到目前为止尚未发现明确的证据。 J/psi介子的衍射弹性产生已在光生极限下测量，直至最高的光子质子质心系能量。 截面的增加由pQCD模型描述。 在较大的Q^2下，W依赖性被发现与光生中观察到的相似。 高t数据的首次分析显示出类似于幂律的|t|依赖性。 LO BFKL计算对数据有良好的描述。 显示英文摘要

摘要： Inelastic and diffractive production of J/psi mesons at HERA is reviewed. The data on inelastic photoproduction are described well within errors by the Colour Singlet Model in next-to-leading order. A search for colour octet processes predicted within the NRQCD/factorisation approach is conducted in many regions of phase space. No unambiguous evidence has been found to date. Diffractive elastic production of J/psi mesons has been measured in the limit of photoproduction up to the highest photon proton center of mass energies. The increase of the cross section is described by pQCD models. At larger Q^2, the W dependence is found to be similar to that observed in photoproduction. First analyses of data at high t yield a powerlike dependence on |t|. A LO BFKL calculation gives a good description of the data.