6533b7d4fe1ef96bd126287d
RESEARCH PRODUCT
Charge asymmetries of top quarks at hadron colliders revisited
German RodrigoGerman RodrigoJohann H. Kühnsubject
QuarkPhysicsNuclear and High Energy PhysicsParticle physicsLarge Hadron Collider010308 nuclear & particles physicsmedia_common.quotation_subjectPhysics beyond the Standard ModelHadronTevatronFísicaFOS: Physical sciences01 natural sciencesAsymmetryHigh Energy Physics - ExperimentStandard ModelHigh Energy Physics - PhenomenologyHigh Energy Physics - Experiment (hep-ex)High Energy Physics - Phenomenology (hep-ph)0103 physical sciencesRapidityHigh Energy Physics::Experiment010306 general physicsmedia_commondescription
A sizeable difference in the differential production cross section of top- compared to antitop-quark production, denoted charge asymmetry, has been observed at the Tevatron. The experimental results seem to exceed the theory predictions based on the Standard Model by a significant amount and have triggered a large number of suggestions for "new physics". In the present paper the Standard Model predictions for Tevatron and LHC experiments are revisited. This includes a reanalysis of electromagnetic as well as weak corrections, leading to a shift of the asymmetry by roughly a factor 1.1 when compared to the results of the first papers on this subject. The impact of cuts on the transverse momentum of the top-antitop system is studied. Restricting the ttbar system to a transverse momentum less than 20 GeV leads to an enhancement of the asymmetries by factors between 1.3 and 1.5, indicating the importance of an improved understanding of the $t\bar t$-momentum distribution. Predictions for similar measurements at the LHC are presented, demonstrating the sensitivity of the large rapidity region both to the Standard Model contribution and effects from "new physics".
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-09-30 |