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Title
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Combined search for the quarks of a sequential fourth generation
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Author
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Institution/Organisation
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CMS Collaboration
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Abstract
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| Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 fb(-1) recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions. DOI: 10.1103/PhysRevD.86.112003 |
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Language
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English
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Source (journal)
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Physical review : D : particles, fields, gravitation, and cosmology / American Physical Society. - Ridge, N.Y., 2004 - 2015
Physical review : D : particles and fields. - Lancaster, Pa, 1970 - 2003
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Publication
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Ridge, N.Y.
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American Physical Society
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2012
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ISSN
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1550-7998
[print]
1550-2368
[online]
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DOI
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10.1103/PHYSREVD.86.112003
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Volume/pages
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86
:11
(2012)
, p. 1-20
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Article Reference
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112003
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ISI
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000312294500001
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Medium
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E-only publicatie
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Full text (Publisher's DOI)
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Full text (open access)
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