Abstract
8 páginas, 3 figuras, 3 tablas.-- CDF Collaboration: et al.
We report the most restrictive direct limits on masses of fourth- generation down- type quarks b0, and quarklike composite fermions (B or T5= 3), decaying promptly to tW -/+. We search for a significant excess of events with two same- charge leptons (e, mu), several hadronic jets, and missing transverse energy. An analysis of data from pp collisions with an integrated luminosity of 2: 7 fb = 1 collected with the CDF II detector at Fermilab yields no evidence for such a signal, setting mass limits mb0, mB > 338 GeV= c2 and mT5= 3 > 365 GeV= c2 at 95% confidence level.
We thank the Fermilab staff and the technical staffs
of the participating institutions for their vital contributions.
This work was supported by the U.S. Department
of Energy and National Science Foundation; the Italian
Istituto Nazionale di Fisica Nucleare; the Ministry of
Education, Culture, Sports, Science and Technology of
Japan; the Natural Sciences and Engineering Research
Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation;
the A.P. Sloan Foundation; the Bundesministerium
für Bildung und Forschung, Germany; the World Class
University Program, the National Research Foundation
of Korea; the Science and Technology Facilities Council
and the Royal Society, UK; the Institut National de
Physique Nucleaire et Physique des Particules/CNRS;
the Russian Foundation for Basic Research; the Ministerio
de Ciencia e Innovación, and Programa Consolider-
Ingenio 2010, Spain; the Slovak R&D Agency; and the
Academy of Finland.
Peer reviewed