# Search for New Bottomlike Quark Pair Decays QQ̅ →(tW∓)(t̅ W±) in Same-Charge Dilepton Events

http://hdl.handle.net/10138/24118

#### Citation

Aaltonen , T , Mehtala , P , Maki , T , Orava , R , Saarikko , H , Osterberg , K & CDF Collaboration 2010 , ' Search for New Bottomlike Quark Pair Decays QQ̅ →(tW∓)(t̅ W±) in Same-Charge Dilepton Events ' , Physical Review Letters , vol 104 , no. 9 , pp. 091801 .

 Title: Search for New Bottomlike Quark Pair Decays QQ̅ →(tW∓)(t̅ W±) in Same-Charge Dilepton Events Author: Aaltonen, T.; Mehtala, P.; Maki, T.; Orava, R.; Saarikko, H.; Osterberg, K.; CDF Collaboration Contributor: University of Helsinki, Department of PhysicsUniversity of Helsinki, Helsinki Institute of PhysicsUniversity of Helsinki, Helsinki Institute of Physics (HIP) (-2009)University of Helsinki, Department of PhysicsUniversity of Helsinki, Department of PhysicsUniversity of Helsinki, Department of Physics Publisher: American Institute of Physics Date: 2010 Number of pages: 8 Belongs to series: Physical Review Letters ISSN: 0031-9007 URI: http://hdl.handle.net/10138/24118 Peer reviewed: Yes Abstract: We report the most restrictive direct limits on masses of fourth-generation down-type quarks b′, 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, μ), several hadronic jets, and missing transverse energy. An analysis of data from pp̅ 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 mb′, mB>338  GeV/c2 and mT5/3>365  GeV/c2 at 95% confidence level.We report the most restrictive direct limits on masses of fourth-generation down-type quarks $b^{\prime}$, and quark-like composite fermions ($B$ or $T_{5/3}$), decaying promptly to $t W^{\mp}$. 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 $p\overline{p}$ 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 $m_{b^{\prime}}, m_{B} >$ 338 $\mathrm{GeV}/c^2$ and $m_{T_{5/3}} >$ 365 $\mathrm{GeV}/c^2$ at 95% confidence level. Subject: 114 Physical sciences
﻿