Mixed QCD and weak corrections to top quark pair production at hadron colliders

Abstract

The order $α_s^2 α$ mixed QCD and weak corrections to top quark pair production by quark antiquark annihilation are computed, keeping the full dependence on the $t$ and $\bar t$ spins. We determine the contributions to the cross section and to single and double top spin asymmetries at the parton level. These results are necessary ingredients for precise standard model predictions of top quark observables, in particular of top spin-induced parity-violating angular correlations and asymmetries at hadron colliders.

Figures (9)

• Figure 1: Dimensionless scaling functions $f^{(0)}_{q \bar{q}}(\eta)$ (dashed), $f^{(1)}_{q \bar{q}}(\eta)$ (solid) that determine the parton cross section (\ref{['eq:xsection']}) for $q=d$ type quarks. The dash-dotted and dotted lines correspond to the respective functions for $q=u$ type quarks. The Higgs boson mass is put to 114 GeV.
• Figure 2: Contributions of the initial and final vertex corrections for $m_H$= 114 GeV (dashed), for $m_H$ = 250 GeV (dash-dotted), and of the box plus gluon radiation terms (solid) to $f^{(1)}_{d \bar{d}}(\eta)$.
• Figure 3: Contributions of the LO (solid) and NLO QCD (dashed) contributions (taken from Bernreuther:2000yn) and of the mixed $\alpha_s^2 \alpha$ contributions (dotted and dash-dotted line refers to initial d-type and u-type quarks, respectively) to the cross section (\ref{['mixed']}) in units of $1/m_t^2$, and $m_H$ = 114 GeV.
• Figure 4: Scaling functions $h^{(0,a)}_{q \bar{q}}(\eta)$ (dashed), $h^{(1,a)}_{q \bar{q}}(\eta)$ (solid) that determine the expectation value (\ref{['eq:sinspin']}) for the beam axis in the case of $q=d$ type quarks. The dash-dotted and dotted lines correspond to the respective functions for $q=u$ type quarks. $m_H$ = 114 GeV.
• Figure 5: Scaling functions $h^{(0,a)}_{q \bar{q}}(\eta)$ (dashed), $h^{(1,a)}_{q \bar{q}}(\eta)$ (solid) that determine the expectation value (\ref{['eq:sinspin']}) for the off-diagonal axis in the case of $q=d$ type quarks. The dash-dotted and dotted lines correspond to the respective functions for $q=u$ type quarks. $m_H$ = 114 GeV.