Ahmed Taushif, Bonvini Marco, Kumar M C, Mathews Prakash, Rana Narayan, Ravindran V, Rottoli Luca
The Institute of Mathematical Sciences, IV Cross Road CIT Campus, Taramani, Chennai, 600113 India.
Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford, OX1 3NP UK.
Eur Phys J C Part Fields. 2016;76(12):663. doi: 10.1140/epjc/s10052-016-4510-1. Epub 2016 Dec 1.
We consider the production of a pseudo-scalar particle at the LHC, and present accurate theoretical predictions for its inclusive cross section in gluon fusion. The prediction is based on combining fixed-order perturbation theory and all-order threshold resummation. At fixed order we include the exact next-to-next-to-leading order (NNLO) plus an approximate next-to-next-to-next-to-leading order (N[Formula: see text]LO[Formula: see text]) which is based on the recent computation at this order for the scalar case. We then add threshold resummation at next-to-next-to-next-to leading logarithmic accuracy (N[Formula: see text]LL[Formula: see text]). Various forms of threshold resummation are considered, differing by the treatment of subleading terms, allowing a robust estimate of the theoretical uncertainties due to missing higher orders. With particular attention to pseudo-scalar masses of 200 and 750 GeV, we also observe that perturbative convergence is much improved when resummation is included. Additionally, results obtained with threshold resummation in direct QCD are compared with analogous results as computed in soft-collinear effective theory, which turn out to be in good agreement. We provide precise predictions for pseudo-scalar inclusive cross section at 13 TeV LHC for a wide range of masses. The results are available through updated versions of the public codes ggHiggs and TROLL.
我们考虑在大型强子对撞机（LHC）中产生一个赝标量粒子，并给出其在胶子融合过程中包含性截面的精确理论预测。该预测基于固定阶微扰理论和全阶阈值重整化的结合。在固定阶，我们包括精确的次下一个领头阶（NNLO）加上一个基于标量情形下该阶次近期计算的近似次次下一个领头阶（N³LO）。然后我们添加次下一个领头对数精度（N³LL）的阈值重整化。考虑了各种形式的阈值重整化，它们在次领头项的处理上有所不同，从而能够对由于缺失高阶项而导致的理论不确定性进行稳健估计。特别关注200 GeV和750 GeV的赝标量质量，我们还观察到当包含重整化时微扰收敛性有很大改善。此外，将直接QCD中阈值重整化得到的结果与软共线有效理论中计算的类似结果进行了比较，结果显示吻合良好。我们给出了13 TeV LHC下广泛质量范围内赝标量包含性截面的精确预测。结果可通过公共代码ggHiggs和TROLL的更新版本获取。
