We report on a search for the non-standard-model process u(c) + g -> t using p anti-p collision data collected by the CDF II detector corresponding to 2.2 fb-1. The candidate events are classified as signal-like or background-like by an artificial neural network. The observed discriminant distribution yields no evidence for FCNC top-quark production, resulting in an upper limit on the production cross section sigma(u(c) + g > t) < 1.8 pb at the 95% C.L. Using theoretical predictions we convert the cross-section limit to upper limits on FCNC branching ratios: B(t --> u + g) < 3.9 x 10-4 and B(t --> c + g) < 5.7 x 10-3.
A. Castro, M. Deninno, P. Mazzanti, N. Moggi, F. Rimondi, F. Semeria, et al. (2009). Search for Top-Quark Production via Flavor-Changing Neutral Currents in W + 1 Jet Events at CDF. PHYSICAL REVIEW LETTERS, 102, 151801-1-151801-7 [10.1103/PhysRevLett.102.151801].
Search for Top-Quark Production via Flavor-Changing Neutral Currents in W + 1 Jet Events at CDF
CASTRO, ANDREA;DENINNO, MARIA MADDALENA;MOGGI, NICCOLO';RIMONDI, FRANCO;ZUCCHELLI, STEFANO
2009
Abstract
We report on a search for the non-standard-model process u(c) + g -> t using p anti-p collision data collected by the CDF II detector corresponding to 2.2 fb-1. The candidate events are classified as signal-like or background-like by an artificial neural network. The observed discriminant distribution yields no evidence for FCNC top-quark production, resulting in an upper limit on the production cross section sigma(u(c) + g > t) < 1.8 pb at the 95% C.L. Using theoretical predictions we convert the cross-section limit to upper limits on FCNC branching ratios: B(t --> u + g) < 3.9 x 10-4 and B(t --> c + g) < 5.7 x 10-3.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
