Campbell John, Carena Marcela, Harnik Roni, Liu Zhen
Theoretical Physics Department, Fermilab, Batavia, Illinois 60510, USA.
Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA.
Phys Rev Lett. 2017 Nov 3;119(18):181801. doi: 10.1103/PhysRevLett.119.181801. Epub 2017 Oct 30.
We consider interference between the Higgs signal and QCD background in gg→h→γγ and its effect on the on-shell Higgs rate. The existence of sizable strong phases leads to destructive interference of about 2% of the on-shell cross section in the standard model. This effect can be enhanced by beyond the standard model physics. In particular, since it scales differently from the usual rates, the presence of interference allows indirect limits to be placed on the Higgs width in a novel way, using on-shell rate measurements. Our study motivates further QCD calculations to reduce uncertainties. We discuss possible width-sensitive observables, both using total and differential rates and find that the HL-LHC can potentially indirectly constrain widths of order tens of MeV.
我们考虑了在gg→h→γγ过程中希格斯信号与量子色动力学（QCD）背景之间的干涉及其对壳上希格斯产生率的影响。可观的强相位的存在导致标准模型中约2%的壳上截面产生相消干涉。这种效应可以通过超出标准模型的物理机制得到增强。特别是，由于它与通常的产生率具有不同的标度，干涉的存在使得可以利用壳上产生率测量以一种新颖的方式对希格斯宽度进行间接限制。我们的研究促使进一步进行QCD计算以降低不确定性。我们讨论了可能对宽度敏感的可观测量，包括使用总产生率和微分产生率，并发现高亮度大型强子对撞机（HL-LHC）有可能间接约束几十兆电子伏特量级的宽度。
