Implications of the CDF $ t\bar{t} $ forward-backward asymmetry for hard top physics

• DOI: 10.1007/jhep08(2011)031
• Publication Date: 2011-08-08T21:35:12Z
• Authors: Cédric Delaunay; Oram Gedalia; Yonit Hochberg; Gilad Perez; Yotam Soreq
• Keywords: High Energy Physics - Phenomenology; High Energy Physics - Phenomenology (hep-ph); 0103 physical sciences; FOS: Physical sciences; 01 natural sciences

The CDF collaboration has recently reported a large deviation from the standard model of the t \bar t forward-backward asymmetry in the high invariant mass region. We interpret this measurement as coming from new physics at a heavy scale Lambda, and perform a model-independent analysis up to O(1/Lambda^4). A simple formalism to test and constrain models of new physics is provided. We find that a large asymmetry cannot be accommodated by heavy new physics that does not interfere with the standard model. We show that a smoking gun test for the heavy new physics hypothesis is a significant deviation from the standard model prediction for the t \bar t differential cross section at large invariant mass. At M_{t\bar t}>1 TeV the cross section is predicted to be at least twice that of the SM at the Tevatron, and for M_{t\bar t}>1.5 TeV at least three times larger than the SM at the LHC.<br/>12 pages, 3 figures. v2: Minor corrections in the text, references added. v3: Extended discussion on QCD NLO corrections, added short discussion on LHC dijet constraints; matches published version<br/>