Electroweak Sudakov Corrections and the Top Quark Forward-Backward Asymmetry

TL;DR

This paper calculates electroweak Sudakov corrections to the top quark forward-backward asymmetry and invariant mass spectra, showing significant effects on SM predictions and experimental measurements at high energies.

Contribution

It provides the first detailed analysis of electroweak Sudakov effects on top quark asymmetry and invariant mass distributions at the LHC.

Findings

Electroweak Sudakov corrections increase the SM asymmetry prediction by 5%.

Corrections reduce the dijet and t-tbar spectra by approximately 20% and 10%.

Shape of high-mass tail in spectra is significantly altered.

Abstract

The Standard Model (SM) prediction of the top quark forward backward asymmetry is shown to be slightly enhanced by a correction factor of 1.05 due to electroweak Sudakov (EWS) logarithms of the form (\alpha/sin^2 \theta_W)^n log^{m< 2n} (s/M_{W,Z}^2). The EWS effect on the dijet and t \bar{t} invariant mass spectra is significant, reducing the SM prediction by ~20, 10 % respectively for the highest invariant masses measured at the LHC, and changing the shape of the high-mass tail of the spectrum. These corrections significantly affect measurements of the top quark invariant mass spectrum and the search for an excess of events related to the top quark forward-backward asymmetry.