Dijet Invariant Mass Distribution in Top Quark Hadronic Decay with QCD Corrections

TL;DR

This paper calculates the dijet invariant mass distribution from top quark decay including NLO QCD corrections, comparing jet algorithms to aid in distinguishing signals and understanding the CDF $Wjj$ anomaly.

Contribution

It provides analytical expressions for the dijet mass distribution in top decay with NLO QCD corrections, considering different jet algorithms and regularization schemes.

Findings

NLO QCD corrections significantly affect the dijet mass distribution.

Different jet algorithms influence the shape of the dijet mass spectrum.

Results help distinguish top decay jets from other sources and clarify the CDF $Wjj$ anomaly.

Abstract

The dijet invariant mass distributions from the hadronic decay of unpolarized top quark ($t\to b W^+$ followed by $W^+\to u \bar{d}$) are calculated, including the next-to-leading order QCD radiative corrections. We treat the top decay in the complex mass scheme due to the existence of the intermediate state W boson. Our analytical expressions are also available in different dimensional regularization schemes and $\gamma_5$ strategies. Finally, in order to construct the jets, we use different jet algorithms to compare their influences on our results. The obtained dijet mass distributions from the top quark decay are useful to distinguish these dijets from those produced via other sources and to clarify the issue about the recent CDF Collaborations' $Wjj$ anomaly.