Search for vectorlike light-flavor quark partners in proton-proton collisions at s =8 TeV
A search is presented for heavy vectorlike quarks (VLQs) that couple only to light quarks in protonproton collisions at ffiffi s p ¼ 8 TeV at the LHC. The data were collected by the CMS experiment during 2012 and correspond to an integrated luminosity of 19.7 fb−1. Both single and pair production...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English English |
| Published: |
American Physical Society
2018
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/65674/ http://irep.iium.edu.my/65674/ http://irep.iium.edu.my/65674/ http://irep.iium.edu.my/65674/1/65674_Search%20for%20vectorlike%20light-flavor%20quark%20partners_article.pdf http://irep.iium.edu.my/65674/2/65674_Search%20for%20vectorlike%20light-flavor%20quark%20partners_scopus.pdf |
| Summary: | A search is presented for heavy vectorlike quarks (VLQs) that couple only to light quarks in protonproton
collisions at ffiffi
s p ¼ 8 TeV at the LHC. The data were collected by the CMS experiment during 2012
and correspond to an integrated luminosity of 19.7 fb−1. Both single and pair production of VLQs are
considered. The single-production search is performed for down-type VLQs (electric charge of magnitude
1=3), while the pair-production search is sensitive to up-type (charge of magnitude 2=3) and down-type
VLQs. Final states with at least one muon or one electron are considered. No significant excess over
standard model expectations is observed, and lower limits on the mass of VLQs are derived. The lower
limits range from 400 to 1800 GeV, depending on the single-production cross section and the VLQ
branching fractions B to W, Z, and Higgs bosons. When considering pair production alone, VLQs
with masses below 845 GeV are excluded for BðWÞ ¼ 1.0, and below 685 GeV for BðWÞ ¼ 0.5,
BðZÞ ¼ BðHÞ ¼ 0.25. The results are more stringent than those previously obtained for single and pair
production of VLQs coupled to light quarks. |
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