在PYTHIA、HERWIG、ALPGEN和SHERPA中实施的LHC的包容性Z/伽马 * 生产中的基质元素校正研究
A study on Matrix Element corrections in inclusive Z/ gamma* production at LHC as implemented in PYTHIA, HERWIG, ALPGEN and SHERPA
摘要：
我们研究了强子碰撞的四个流行事件发生器中的矩阵元修正。我们比较PYTHIA，HERWIG，ALPGEN和SHERPA在LHC的Z/gamma* 包容性生产。PYTHIA和HERWIG能够校正簇射的第一次发射，同时考虑到一个额外部分子的矩阵元计算。SHERPA和ALPGEN能够考虑矩阵元修正，不仅对一个，而是对几个硬排放从传入的部分子。这可以在引入分离切割以区分矩阵元素和Parton簇射填充区域的代价下完成。在本文中，我们检查PYTHIA和HERWIG中的矩阵元素校正的效果，我们检查这两个生成器的结果是一致的。然后我们转向SHERPA和ALPGEN，它们实现了两种不同的方法来匹配矩阵元计算和Parton Shower。如果我们约束它们，使它们不能从矩阵元计算中出现一个以上的部分子，它们都应该给出类似于PYTHIA和HERWIG的结果。换句话说，PYTHIA和HERWIG为我们提供了正确的参考，以发现SHERPA和ALPGEN中实施的匹配处方可能存在的问题。我们还检查了在多大程度上的依赖矩阵元素- Parton淋浴分离切割被取消在这两个发电机。
英文摘要：
We study Matrix Element corrections as implemented in four popular event generators for hadron collisions. We compare PYTHIA, HERWIG, ALPGEN and SHERPA in the Z/gamma* inclusive production at LHC. PYTHIA and HERWIG are able to correct the first emission from the shower taking the Matrix Element calculation for one additional parton into account. SHERPA and ALPGEN are able to take into account Matrix Element corrections not only for one, but rather for several hard emissions from the incoming partons. This can be done at the price of introducing a separation cut to distinguish a Matrix Element and a Parton Shower populated regions. In this paper we check the effect of Matrix Element corrections in PYTHIA and HERWIG and we check that results from these two generators are consistent. Then we turn to SHERPA and ALPGEN, that implement two different methods to match Matrix Element calculations and Parton Shower. If we constraint them so that no more than one parton can emerge from the Matrix Element calculations they should both give results similar to PYTHIA and HERWIG. In other words PYTHIA and HERWIG provide us with the correct reference to spot possible issues with the matching prescriptions implemented in SHERPA and ALPGEN. We also check to what extent the dependency on the Matrix Element - Parton Shower separation cut is canceled in these two generators.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
