Abstract
We report the most sensitive direct search for pair production of fourth-generation bottomlike chiral quarks () each decaying promptly to . We search for an excess of events with an electron or muon, at least five jets (one identified as due to a or quark), and an imbalance of transverse momentum by using data from collisions collected by the CDF II detector at Fermilab with an integrated luminosity of . We observe events consistent with background expectation, calculate upper limits on the pair-production cross section ( for ), and exclude at 95% confidence level assuming a 100% branching ratio of to .
- Received 29 January 2011
DOI:https://doi.org/10.1103/PhysRevLett.106.141803
© 2011 American Physical Society