The top quark rapidity distribution and forward-backward asymmetry

TL;DR

The study provides precise SM predictions for the top-quark rapidity distribution and forward-backward asymmetry using NNLL resummation to generate approximate NNLO corrections. It computes dσ/dY at LHC energies (7 and 14 TeV) and the Tevatron energy (1.96 TeV), showing NNLO corrections enhance the distributions and reduce scale dependence, with the LHC displaying near symmetry due to gg dominance. The Tevatron A_FB is predicted to be about 5.2%, significantly smaller than measured values, highlighting a persistent tension and the potential to signal new physics beyond the Standard Model. These results offer robust theoretical benchmarks for ongoing collider analyses and future precision tests of top-quark production dynamics.

Abstract

I present results for the top quark rapidity distribution at LHC and Tevatron energies, including higher-order corrections from threshold resummation. The next-to-next-to-leading-order (NNLO) soft-gluon corrections at next-to-next-to-leading-logarithm (NNLL) level are added to the NLO result. Theoretical predictions are shown for the rapidity distribution, including the scale dependence of the distributions. The forward-backward asymmetry at the Tevatron is also calculated.

Figures (6)

• Figure 1: The top quark rapidity distribution at the LHC with $\sqrt{S}=7$ TeV, $m=173$ GeV, and $\mu=m/2$, $m$, $2m$.
• Figure 2: The top quark rapidity distribution at the LHC with $\sqrt{S}=7$ TeV and $\mu=m=173$ GeV in a logarithmic plot.
• Figure 3: The top quark rapidity distribution at the LHC with $\sqrt{S}=14$ TeV, $m=173$ GeV, and $\mu=m/2$, $m$, $2m$.
• Figure 4: The top quark rapidity distribution at the LHC with $\sqrt{S}=14$ TeV and $\mu=m=173$ GeV in a logarithmic plot.
• Figure 5: The top quark rapidity distribution at the Tevatron with $\sqrt{S}=1.96$ TeV, $m=173$ GeV, and $\mu=m/2$, $m$, $2m$.