On the top-antitop invariant mass spectrum at the LHC from a Higgs boson signal perspective

TL;DR

This paper analyzes one-loop electroweak corrections to the top-antitop invariant mass spectrum at the LHC, revealing that non-resonant Higgs effects can dominate over resonant contributions and significantly alter the expected interference patterns.

Contribution

It provides a detailed calculation of electroweak corrections involving both resonant and non-resonant Higgs effects, showing their impact on the top-antitop spectrum at the LHC.

Findings

Non-resonant Higgs effects are comparable or larger than resonant ones.

Electroweak corrections can overshadow the traditional peak-dip interference pattern.

The overall spectrum is significantly affected by these higher-order corrections.

Abstract

We investigate the effect of one-loop corrections of ${\cal O}(\alpha_S^2\alpha_W)$ on the $t\bar t$ invariant mass spectrum at the Large Hadron Collider (LHC) in presence of both resonant and non-resonant Higgs boson effects. We show that corrections of ${\cal O}(\alpha_S^2\alpha_W)$ involving a non-resonant Higgs boson are comparable to or even larger than those involving interference with the s-channel resonant Higgs boson amplitude and that both of these are subleading with respect to all other (non-Higgs) diagrams through that order. We also compute the contribution through ${\cal O}(\alpha_S^2\alpha_W^2)$ of resonant Higgs boson production (i.e. Higgs production via $gg$ fusion) as well as the pure QCD ones of ${\cal O}(\alpha_S^3)$. Altogether, we show that the well known peak-dip structure of the $M_{t\bar t}$ spectrum emerging from interference effects between the $t,u$-channel $gg$-induced Leading Order (LO) QCD diagrams and the one due to a Higgs boson in s-channel via $gg$-fusion is drastically swamped by the remainder of the terms of ${\cal O}(\alpha_S^2\alpha_W)$ discussed above.