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arXiv · 1106.2142

Search for same-sign top-quark pair production at sqrt(s) = 7 TeV and limits on flavour changing neutral currents in the top sector

CMS Collaboration
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Abstract

An inclusive search for same-sign top-quark pair production in pp collisions at sqrt(s) = 7 TeV is performed using a data sample recorded with the CMS detector in 2010, corresponding to an integrated luminosity of 35 inverse picobarns. This analysis is motivated by recent studies of p p-bar to t t-bar reporting mass-dependent forward-backward asymmetries larger than expected from the standard model. These asymmetries could be due to Flavor Changing Neutral Currents (FCNC) in the top sector induced by t-channel exchange of a massive neutral vector boson (Z'). Models with such a Z' also predict enhancement of same-sign top-pair production in pp or p p-bar collisions. Limits are set as a function of the Z' mass and its couplings to u and t quarks. These limits disfavour the FCNC interpretation of the Tevatron results.

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CMS Collaboration. 2014-11-10. Search for same-sign top-quark pair production at sqrt(s) = 7 TeV and limits on flavour changing neutral currents in the top sector. https://doi.org/10.1007/jhep08(2011)005

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