标题： 重正化尺度在HERA二喷注产生中的依赖性 显示英文标题

标题： Renormalisation Scale Dependencies in Dijet Production at HERA

摘要： 不同选择的重整化尺度（muren）可用于描述HERA中深度非弹性散射中，具有两个喷注且横动量较大的硬散射过程，通过固定阶微扰QCD计算。 对于领先阶（LO）和下一阶（NLO）计算，最简单的选择是Q2，即入射光子的虚度，以及两个喷注的横动量平方的平均值ET2，在不同的运动学区域中进行了研究。 发现只有当Q2和ET2都较大时，NLO计算相对于muren的数值变化是稳定的，而LO计算则强烈依赖于它。 如果两个尺度中的一个较大，即Q2或ET2，NLO计算比LO计算更稳定，但仍然表现出强烈的剩余尺度依赖性。 当两个尺度相对较小，两种情况下都发现了大的尺度依赖性。 此外，发现LO和NLO计算之间存在较大的差异。 通常，使用ET2作为重整化尺度优于Q2，因为尺度依赖性不那么明显，且NLO修正较小。 显示英文摘要

摘要： Different choices of the renormalisation scale (muren) can be used to describe hard scattering processes with two jets at large transverse momentum in deep-inelastic scattering at HERA by fixed order perturbative QCD calculations. For leading (LO) and next-to-leading order (NLO) calculations the simplest choices, Q2, the virtuality of the incoming photon, and the mean squared transverse momenta of the two jets ET2, are studied in different kinematic regimes. It is found that only if both Q2 and ET2 are large, the NLO calculation is stable with respect to numerical variations of muren while the LO calculation strongly depends on it. If only one of the two scales, either Q2 or ET2, is large, the NLO is more stable than the LO calculation, but exhibits nevertheless a strong residual scale dependence. When both scales are relatively small, large scale dependencies are found in both cases. Moreover, large differences between the LO and NLO calculation are found. Generally, the use of ET2 as renormalisation scale is favoured over Q2, since scale dependencies are less pronounced and NLO corrections are smaller.