A limit on top quark pair production at future electron-proton colliders

TL;DR

This paper establishes theoretical bounds on top quark pair production at future electron-proton colliders using structure function ratios, providing insights into top saturation effects and the potential for new physics exploration.

Contribution

It introduces a compact formula for the ratio of structure functions in top pair production, enabling bounds on top production cross-sections at future colliders, and analyzes top saturation behavior.

Findings

Bound values for top pair production at LHeC and FCC-eh energies.

Limited top saturation effects are expected in future colliders.

Modified scaling improves the understanding of top cross-section behavior.

Abstract

The ratio of the structure functions for deep inelastic scattering in top pair production at future electron-proton colliders is analyzed at a fixed $\sqrt{s}$ and $Q^2$ relative to the minimum value of $x$ given by $Q^2/s$ using collinear factorization. This compact formula for the ratio $F_{L2}(Q^2/s,Q^2,m_{t})$ is useful for extracting a bound on the top structure function. The reduced cross-section for top production at this limit is determined, establishing a bound value for $t\overline{t}$ production at the LHeC and FCC-eh center-of-mass energies based on renormalization scales. The modification of the Bjorken scaling is applied to this bound of the reduced top cross-section at the renormalization scale $\mu^2=Q^2+4m_{t}^{2}$, which improves the scaling quantity at $Q^2{<}4m_{t}^{2}$. The dipole cross-section for top pair production is examined across a wide range of dipole sizes, denoted as $r$. It is expected that there will be limited behavior in observing top saturation in future electron-proton colliders according to the bound behavior. The probability of the Higgs boson in $\gamma^{*}g$ interactions is compared to the $gg$ process at the order of $\mathcal{O}(\alpha^{\mathrm{em}}/\alpha_{s})$.