Abstract
We report the most restrictive direct limits on masses of fourth-generation down-type quarks , and quarklike composite fermions ( or ), decaying promptly to . We search for a significant excess of events with two same-charge leptons (, ), several hadronic jets, and missing transverse energy. An analysis of data from collisions with an integrated luminosity of collected with the CDF II detector at Fermilab yields no evidence for such a signal, setting mass limits , and at 95% confidence level.
- Received 5 December 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.091801
©2010 American Physical Society