Measurement of the fraction of t(t)over-bar production via gluon-gluon fusion in p(p)over-bar collisions at root s=1.96 Tev

• Main Authors: Xie, Si (Contributor), Makhoul, K. (Contributor), Knuteson, Bruce O. (Contributor), Henderson, C. (Contributor), Hahn, Kristian Allan (Contributor), Goncharov, Maxim (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Bauer, Gerry P. (Contributor), Choudalakis, Georgios (Contributor)
• Other Authors: Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2010-01-08T21:53:29Z.
• Subjects: Article
• Online Access: Get fulltext

 We present a measurement of the ratio of the tt̅ production cross section via gluon-gluon fusion to the total tt̅ production cross section in pp̅ collisions at √s=1.96  TeV at the Tevatron. Using a data sample with an integrated luminosity of 955  pb[superscript -1] recorded by the CDF II detector at Fermilab, we select events based on the tt̅ decay to lepton+jets. Using an artificial neural network technique we discriminate between tt̅ events produced via qq̅ annihilation and gg fusion, and find Gf=σ(gg→tt̅ )/σ(pp̅ →tt̅ )<0.33 at the 68% confidence level. This result is combined with a previous measurement to obtain the most stringent measurement of this quantity by CDF to date, Gf=0.07[subscript -0.07][superscript +0.15].