We present a search for a new heavy particle X produced in
association with a top quark, pp̅ →t(X→t̅ q) or pp̅ →t̅
(X̅ →tq̅ ), where q stands for up quarks and down quarks. Such
a particle may explain the recent anomalous measurements of top-quark
forward-backward asymmetry. If the light-flavor quark (q) is reconstructed
as a jet (j), this gives a t̅ +j or t+j resonance in tt̅ +jet events,
a previously unexplored experimental signature. In a sample of events with
exactly one lepton, missing transverse momentum and at least five jets,
corresponding to an integrated luminosity of 8.7 fb-1 collected by
the CDF II detector, we find the data to be consistent with the standard
model. We set cross-section upper limits on the production (pp̅ →Xt
or X̅ t̅ ) at 95% confidence level from 0.61 pb to 0.02 pb for X
masses ranging from 200 GeV/c2 to 800 GeV/c2, respectively.
Return to top of page.
Go to Physics Results
Updated: Wednesday, 2012 October 17 09:36:01 CDT automatically from input from Stephanie A Schuler