2011/07/31 by Moira I. Gresham, Ian-Woo Kim, Kathryn M. Zurek
Mathematics · Physics and Astronomy · #Asymmetry #Geometry #High-Energy Particle Collisions Research #Invariant (physics) #Invariant mass #Large Hadron Collider #Mathematical physics #Mathematics #Nuclear physics #Observable #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Scalar (mathematics) #Tevatron #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.85.014022
51 pages, 25 figures, 7 tables; v2: refs. added, typos fixed, figures improved, notes added
arxiv created 2011/08/12 · openalex publication_date 2012/01/20 · arxiv updated 2015/03/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We carry out a comprehensive analysis of models for top AFB at CDF in light of new top data arriving from the LHC. We begin with a careful Tevatron analysis, considering in general which sets of effective vertices give rise to a large forward-backward asymmetry while suppressing the contribution to the total tt cross-section. We show on general grounds that scalar models struggle to produce sufficient asymmetries consistent with CDF observations, while vector models can produce a large asymmetry with a less significant tension in the total cross-section and tt invariant mass distribution at the Tevatron. We examine the essential observables of these models for top physics at LHC7 with 1 fb^\ensuremath-1 of data, including the total cross-section, invariant mass distribution and number of additional jets in tt events. In the case of t-channel mediators, the LHC total cross-section places a strong constraint on light mediators, while the Tevatron invariant mass distributions place strong constraints on heavy mediators that are able to produce the asymmetry. In particular, single mediator production at the LHC can contribute significantly to tt+jets events and lead to a significant increase in the tt cross-section, as well as in the ratio of top pair events with extra jets to events with no extra jets. Heavy axigluons are becoming increasingly squeezed by LHC7 tt and dijet resonance searches. We conclude that LHC7 top analyses are rapidly closing the window for viable models of the CDF top AFB.