Damping of forward neutrons in pp collisions
Damping of forward neutrons in pp collisions
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pp 碰撞中前向中子的阻尼
DOI：
10.1103/physrevd.78.014031
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发表时间：
2008
影响因子：
5
通讯作者：
J. Soffer
中科院分区：
文献类型：
--
作者：
B. Kopeliovich;I. Potashnikova;I. Schmidt;J. Soffer
我们计算了pp碰撞中前导中子产生过程中单介子交换的吸收修正。与通常将生存概率与横截面进行卷积的程序相反，我们对自旋振幅进行修正。非翻转振幅比自旋翻转振幅更容易被吸收抑制。我们确定了负责吸收校正的抛射质子Fock态为彩色八元-八元五夸克构型。在两种非常不同的模型中计算，彩色偶极子光锥描述和强子表示，导致相当相似的吸收修正。我们发现前导中子的阻尼比之前估计的要大得多。相应的，截面比ISR测得的要小得多。然而，与ZEUS合作项目最近测量的深度非弹性散射中子产生的数据进行比较，为挑战ISR数据的归一化提供了强大的动力。这一猜想也得到了在SPS上pp碰撞产生中子的NA49实验的初步数据的支持。
We calculate absorptive corrections to single pion exchange in the production of leading neutrons in pp collisions. Contrary to the usual procedure of convolving the survival probability with the cross section, we apply corrections to the spin amplitudes. The nonflip amplitude turns out to be much more suppressed by absorption than the spin-flip one. We identify the projectile proton Fock state responsible for the absorptive corrections as a color octet-octet 5-quarks configuration. Calculations within two very different models, color-dipole light-cone description, and in hadronic representation, lead to rather similar absorptive corrections. We found a much stronger damping of leading neutrons than in some of previous estimates. Correspondingly, the cross section is considerably smaller than was measured at ISR. However, comparison with recent measurements by the ZEUS collaboration of neutron production in deep-inelastic scattering provides a strong motivation for challenging the normalization of the ISR data. This conjecture is also supported by preliminary data from the NA49 experiment for neutron production in pp collisions at SPS.