论文标题
在LHC的顶级对生产中预计的横向动量重新调整
Projected transverse momentum resummation in top-antitop pair production at LHC
论文作者
论文摘要
$ t \ bar {t} $系统的横向动量分布既具有实验性和理论利益。在存在方位角不对称的差异的情况下，在高对数精度上追求重新召集通常要求。在本文中，我们提出了投影的横向动量频谱$ \ mathrm {d}σ_{t \ bar {t}}/\ mathrm {d}q_τ$，该q_τ$源自经典$ \ vec {q} _ {Q} _ {\ nathrm {\ mathrm {\ nathrm {相对于参考单位向量$ \vecτ$，$ q_ {τ_ {\ perp}} $，作为抑制这些不对称影响的替代解决方案，除了相对平均的情况外， | \ vec {q} _ {\ mathrm {t}} | $。在有效的领域理论的上下文中，cot $ _ {\ mathrm {ii}} $和hqet，我们将证明，尽管$ q_ {τ_{τ_{\ perp}} $ Integrations是$ \ mathrm {d} f的领先的差异术语，仍然可以根据$q_τ= 0 $ 〜gev附近的硬，梁和软函数来观察分解模式。借助肾小效应组方程技术，我们评估了重新亮相频谱$ \ mathrm {d}σ_{t \ bar {t}}/\ mathrm {d} q _ { $ \ MATHRM {d}σ_{ NLL+NLO，NNLL+NNLO和近似NNLL'+NNLO精度。这是方位角频谱$Δφ__{t \ bar {t}} $在NNLL级别上进行评估，包括对光束胶线和软辐射的一致处理。
The transverse momentum distribution of the $t\bar{t}$ system is of both experimental and theoretical interest. In the presence of the azimuthally asymmetric divergences, pursuing the resummation at the high logarithmic precision is rather demanding in general. In this paper, we propose the projected transverse momentum spectrum $\mathrm{d}σ_{t\bar{t}}/\mathrm{d} q_τ$, which is derived from the classical $\vec{q}_{\mathrm{T}}$ spectrum by integrating out the rejection component $q_{τ_{\perp}}$ with respect to a reference unit vector $\vecτ$, to serve as an alternative resolution to curb those asymmetric influences, in additional to the azimuthally averaged case $\mathrm{d}σ_{t\bar{t}}/\mathrm{d} |\vec{q}_{\mathrm{T}}|$. In the context of the effective field theories, SCET$_{\mathrm{II}}$ and HQET, we will demonstrate that in spite of the $q_{τ_{\perp}}$ integrations, the leading asymptotic terms of $\mathrm{d}σ_{t\bar{t}}/\mathrm{d} q_τ$ still observe the factorization pattern in terms of the hard, beam, and soft functions in the vicinity of $ q_τ=0$~GeV. With the help of the renormalisation group equation techniques, we evaluate the resummed spectra $\mathrm{d}σ_{t\bar{t}}/\mathrm{d} q_{\mathrm{T,in}}$, $\mathrm{d}σ_{t\bar{t}}/\mathrm{d} q_{\mathrm{T,out}}$, and $\mathrm{d}σ_{t\bar{t}}/\mathrm{d} ΔΦ_{t\bar{t}}$ at NLL+NLO, NNLL+NNLO, and approximate NNLL'+NNLO accuracy. This is the first time the azimuthal spectrum $ΔΦ_{t\bar{t}}$ is appraised at or beyond the NNLL level including a consistent treatment of both beam collinear and soft radiation.
