Next-to-leading order QCD corrections to a heavy resonance production and decay into top quark pair at the LHC

TL;DR

This paper calculates next-to-leading order QCD corrections for heavy resonance production and decay into top quark pairs at the LHC, showing significant cross section enhancements and analyzing angular and spin correlation effects.

Contribution

It provides the first complete NLO QCD calculations for both RS KK graviton and Z' resonance production and decay into top pairs, including detailed angular and spin correlation analyses.

Findings

NLO corrections increase cross sections by 80-100% for KK graviton and 20-40% for Z'

NLO distributions differ from LO for KK graviton angular distributions

Spin correlations are minimally affected by NLO corrections

Abstract

We present a complete next-to-leading order (NLO) QCD calculation to a heavy resonance production and decay into a top quark pair at the LHC, where the resonance could be either a Randall-Sundrum (RS) Kaluza-Klein (KK) graviton $G$ or an extra gauge boson $Z'$. The complete NLO QCD corrections can enhance the total cross sections by about $80\%- 100\%$ and $20\%- 40\%$ for the $G$ and the $Z'$, respectively, depending on the resonance mass. We also explore in detail the NLO corrections to the polar angle distributions of the top quark, and our results show that the shapes of the NLO distributions can be different from the leading order (LO) ones for the KK graviton. Moreover, we study the NLO corrections to the spin correlations of the top quark pair production via the above process, and find that the corrections are small.