${{\mathit t}^{\,'}}$(2/3)-quark/hadron mass limits in ${{\mathit p}}{{\overline{\mathit p}}}$ and ${{\mathit p}}{{\mathit p}}$ collisions

INSPIRE   PDGID:
Q009TPP
VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
$\bf{> 1600}$ 95 1
AAD
2023AV
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1
$> 960$ 95 2
TUMASYAN
2023AX
 CMS EW production, ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit H}}{{\mathit t}}$ ( ${{\mathit H}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$)
$\bf{> 1500}$ 95 3
TUMASYAN
2023V
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit h}}{{\mathit t}}$) = 1
$>980$ 95 4
AABOUD
2018CE
 ATLS ${}\geq{}2{{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}1{{\mathit b}}$j
$> 1030$ 95 5, 6
AABOUD
2018CP
 ATLS 2,3${{\mathit \ell}}$, singlet model
$> 1210$ 95 5, 7
AABOUD
2018CP
 ATLS 2,3${{\mathit \ell}}$, doublet model
$\bf{> 1310}$ 95 8, 9
AABOUD
2018CR
 ATLS singlet ${{\mathit t}^{\,'}}$. ATLAS combination
$\bf{> 1370}$ 95 8, 10
AABOUD
2018CR
 ATLS ${{\mathit t}^{\,'}}$ in a weak isospin doublet (${{\mathit t}^{\,'}},{{\mathit b}^{\,'}}$). ATLAS combination.
$> 1140$ 95 11
SIRUNYAN
2018BM
 CMS ${{\mathit W}}{{\mathit b}}$, ${{\mathit Z}}{{\mathit t}}$, ${{\mathit h}}{{\mathit t}}$ modes
$> 845$ 95 12
SIRUNYAN
2018Q
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit q}}$) = 1 (${{\mathit q}}={{\mathit d}},{{\mathit s}}$)
$\bf{> 1295}$ 95 13
SIRUNYAN
2018W
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1
$>860$ 95 14
SIRUNYAN
2017AU
 CMS
$> 735$ 95 15
AAD
2014AZ
 ATLS B( ${{\mathit b}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit t}}$) = 1
$> 350$ 95 16
AAD
2012BC
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit q}}$)=1 (${{\mathit q}}={{\mathit d}},{{\mathit s}},{{\mathit b}}$)
$> 420$ 95 17
AAD
2012C
 ATLS ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit X}}{{\mathit t}}$ (${\mathit m}_{{{\mathit X}}}<$ 140 GeV)
$> 685$ 95 18
CHATRCHYAN
2012BH
 CMS ${\mathit m}_{{{\mathit b}^{\,'}}}$ = ${\mathit m}_{{{\mathit t}^{\,'}}}$
$> 557$ 95 19
CHATRCHYAN
2012P
 CMS ${{\mathit t}^{\,'}}$ ${{\overline{\mathit t}}^{\,'}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit b}}{{\mathit W}^{-}}{{\overline{\mathit b}}}$ $\rightarrow$ ${{\mathit b}}{{\mathit \ell}^{+}}{{\mathit \nu}}{{\overline{\mathit b}}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$> 1470$ 95 20
AAD
2023AG
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1
$> 1280$ 95 21
SIRUNYAN
2019AQ
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1
$>1370$ 95 22
SIRUNYAN
2019BW
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit h}}{{\mathit t}}$) = 1
$> 1010$ 95 23
AABOUD
2018CL
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit h}}{{\mathit t}}$) = 1
$>1160$ 95 24
AABOUD
2017L
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1
$> 770$ 95 25
AAD
2015AR
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1
$> 590$ 95 26
AAD
2015BY
 ATLS ${{\mathit W}}{{\mathit b}}$, ${{\mathit Z}}{{\mathit t}}$, ${{\mathit h}}{{\mathit t}}$ modes
$> 745$ 95 27
KHACHATRYAN
2015AI
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit h}}{{\mathit t}}$) = 1
$> 700$ 95 28
CHATRCHYAN
2014A
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1
$> 706$ 95 28
CHATRCHYAN
2014A
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1
$> 782$ 95 28
CHATRCHYAN
2014A
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit h}}{{\mathit t}}$) = 1
$> 656$ 95 29
AAD
2013F
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1
$> 625$ 95 30
CHATRCHYAN
2013I
 CMS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1
$> 404$ 95 31
AAD
2012AR
 ATLS B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1
$> 570$ 95 32
CHATRCHYAN
2012BC
 CMS ${{\mathit t}^{\,'}}$ ${{\overline{\mathit t}}^{\,'}}$ $\rightarrow$ ${{\mathit W}^{+}}{{\mathit b}}{{\mathit W}^{-}}{{\overline{\mathit b}}}$
$> 400$ 95 33
AALTONEN
2011AH
 CDF ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit X}}{{\mathit t}}$ (${\mathit m}_{{{\mathit X}}}<$ 70 GeV)
$> 358$ 95 34
AALTONEN
2011AL
 CDF ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$
$> 340$ 95 34
AALTONEN
2011AL
 CDF ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit q}}$ (${{\mathit q}}={{\mathit d}},{{\mathit s}},{{\mathit b}}$)
$> 360$ 95 35
AALTONEN
2011O
 CDF ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit X}}{{\mathit t}}$ (${\mathit m}_{{{\mathit X}}}<$ 100 GeV)
$> 285$ 95 36
ABAZOV
2011Q
 D0 ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit q}}$ (${{\mathit q}}={{\mathit d}},{{\mathit s}},{{\mathit b}}$)
$> 256$ 95 37, 38
AALTONEN
2008H
 CDF ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit q}}$
1  AAD 2023AV based on 139 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. Pair production of vector-like ${{\mathit t}^{\,'}}$ is searched for in the mode ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}$ + ${}\geq{}$2j (${}\geq{}$1b-tagged) + $\not E_T$ or with 3${{\mathit \ell}}$. The data are consistent with the SM background predictions and limits are obtained for different branching ratios.
2  TUMASYAN 2023AX based on 138 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. A vector-like ${{\mathit t}^{\,'}}$ is seached for in the ${{\mathit t}}{+}$ ${{\mathit H}}$ ( ${{\mathit H}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$) decay channel. EW production via a coupling to third-generation quarks of $\kappa _{T}$ = 0.25 is assumed. The branching fractions are assumed to be 50, 25, and 25$\%$, respectively, for ${{\mathit b}}{{\mathit W}}$, ${{\mathit t}}{{\mathit Z}}$, and ${{\mathit t}}{{\mathit H}}$ decays.
3  TUMASYAN 2023V based on 138 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. Pair production of vector-like ${{\mathit t}^{\,'}}$ is seached for in the single-lepton, same-sign charge dilepton and multi-lepton channels. The data are consistent with the SM background predictions and limits are obtained for different branching ratios. Masses below 1.48 TeV are excluded for all decays to third generation quarks.
4  AABOUD 2018CE based on 36.1 fb${}^{-1}$ of proton-proton data taken at $\sqrt {s }$ = 13 TeV. Events including a same-sign lepton pair are used. The limit is for a singlet model, assuming the branching ratios of ${{\mathit t}^{\,'}}$ into ${{\mathit Z}}{{\mathit t}}$, ${{\mathit W}}{{\mathit b}}$ and ${{\mathit H}}{{\mathit t}}$ as predicted by the model.
5  AABOUD 2018CP based on 36.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. Pair and single production of vector-like ${{\mathit t}^{\,'}}$ are seached for with at least one ${{\mathit t}^{\,'}}$ decaying into ${{\mathit Z}}{{\mathit t}}$. In the case of B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit Z}}{{\mathit t}}$) = 1, the limit is ${\mathit m}_{{{\mathit t}^{\,'}}}$ $>$ 1340 GeV.
6  The limit is for the singlet model, assuming that the branching ratios into ${{\mathit Z}}{{\mathit t}}$, ${{\mathit W}}{{\mathit b}}$, and ${{\mathit H}}{{\mathit t}}$ add up to one.
7  The limit is for the doublet model, assuming that the branching ratios into ${{\mathit Z}}{{\mathit t}}$, ${{\mathit W}}{{\mathit b}}$, and ${{\mathit H}}{{\mathit t}}$ add up to one.
8  AABOUD 2018CR based on 36.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. A combination of searches for the pair-produced vector-like ${{\mathit t}^{\,'}}$ in various decay channels ( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$, ${{\mathit Z}}{{\mathit t}}$, ${{\mathit h}}{{\mathit t}}$). Also a model-independent limit is obtained as ${\mathit m}_{{{\mathit t}^{\,'}}}$ $>$ 1.31 TeV, assuming that the branching ratios into ${{\mathit Z}}{{\mathit t}}$, ${{\mathit W}}{{\mathit b}}$ and ${{\mathit h}}{{\mathit t}}$ add up to one.
9  The limit is for the singlet ${{\mathit t}^{\,'}}$.
10  The limit is for ${{\mathit t}^{\,'}}$ in a weak isospin doublet (${{\mathit t}^{\,'}},{{\mathit b}^{\,'}}$) and $\vert {{\mathit V}}_{{{\mathit t}^{\,'}}{{\mathit b}}}\vert $ ${}\ll$ $\vert {{\mathit V}}_{{{\mathit t}}{{\mathit b}^{\,'}}}\vert $.
11  SIRUNYAN 2018BM based on 35.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. The limit is for the pair-produced vector-like ${{\mathit t}^{\,'}}$. Three channels (single lepton, same-charge 2 leptons, or at least 3 leptons) are considered for various branching fraction combinations. Assuming B(${{\mathit t}}{{\mathit H}}$) = 1, the limit is 1270 GeV and for B(${{\mathit t}}{{\mathit Z}}$) = 1 it is 1300 GeV.
12  SIRUNYAN 2018Q based on 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV. The limit is for the pair-produced vector-like ${{\mathit t}^{\,'}}$ that couple only to light quarks. Constraints for other decay channels (${{\mathit Z}}{{\mathit q}}$ and ${{\mathit H}}{{\mathit q}}$) are also given in the paper.
13  SIRUNYAN 2018W based on 35.8 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. The limit is for the vector-like ${{\mathit t}^{\,'}}$ pair-produced by strong interaction using lepton-plus-jets mode and assuming that B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) is 100%. Generally the measurement sets upper limits on the product of the production cross section and branching faction to ${{\mathit W}}{{\mathit b}}$ for any new pair-produced heavy quark decaying to this channel as a narrow resonance.
14  SIRUNYAN 2017AU based on 2.3-2.6 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. Limit on pair-produced singlet vector-like ${{\mathit t}^{\,'}}$ using one lepton and several jets. The mass bound is given for a ${{\mathit t}^{\,'}}$ transforming as a singlet under the electroweak symmetry group, assumed to decay through ${{\mathit W}}$, ${{\mathit Z}}$ or Higgs boson (which decays to jets) and to a third generation quark. For a doublet, the limit is $>$830 GeV. Other limits are also given in the paper.
15  Based on 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV. No significant excess over SM expectation is found in the search for pair production or single production of ${{\mathit t}^{\,'}}$ in the events with dilepton from a high $p_T$ ${{\mathit Z}}$ and additional jets (${}\geq{}$ 1 ${{\mathit b}}$-tag). If instead of B( ${{\mathit b}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit t}}$) = 1 an electroweak singlet with B( ${{\mathit b}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit t}}$) $\sim{}$ 0.45 is assumed, the limit reduces to 685 GeV.
16  Based on 1.04 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. No signal is found for the search of heavy quark pair production that decay into ${{\mathit W}}$ and a quark in the events with dileptons, large $\not E_T$, and ${}\geq{}$2 jets.
17  Based on 1.04 fb${}^{-1}$ of data in ${{\mathit p}}{{\mathit p}}$ collisions at 7 TeV. AAD 2012C looked for ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production followed by ${{\mathit t}^{\,'}}$ decaying into a top quark and ${{\mathit X}}$, an invisible particle, in a final state with an isolated high-P$_{T}$ lepton, four or more jets, and a large missing transverse energy. No excess over the SM ${{\mathit t}}{{\overline{\mathit t}}}$ production gives the upper limit on ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production cross section as a function of ${\mathit m}_{{{\mathit t}^{\,'}}}$ and ${\mathit m}_{{{\mathit X}}}$. The result is obtained for B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit t}}$) = 1.
18  Based on 5 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. CHATRCHYAN 2012BH searched for QCD and EW production of single and pair of degenerate 4'th generation quarks that decay to ${{\mathit W}}{{\mathit b}}$ or ${{\mathit W}}{{\mathit t}}$. Absence of signal in events with one lepton, same-sign dileptons or tri-leptons gives the bound. With a mass difference of 25 GeV/c${}^{2}$ between ${\mathit m}_{{{\mathit t}^{\,'}}}$ and ${\mathit m}_{{{\mathit b}^{\,'}}}$, the corresponding limit shifts by about $\pm20$ GeV/c${}^{2}$.
19  Based on 5.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. CHATRCHYAN 2012P looked for ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production events with two isolated high $p_T$ leptons, large $\not E_T$, and 2 high $p_T$ jets with ${{\mathit b}}$-tag. The absence of signal above the SM background gives the limit for B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1.
20  AAD 2023AG based on 139 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. Pair production of vector-like top or bs is searched for in the mode 1${{\mathit \ell}}$ + ${}\geq{}$4j(${}\geq{}$1b-tagged) + $\not E_T$. The data are consistent with the SM background predictions and limits are obtained for different branching ratios. Masses below 1.59 TeV are excluded assuming a mass-degenerate vector-like doublet (${{\mathit t}^{\,'}},{{\mathit b}^{\,'}}$) model.
21  SIRUNYAN 2019AQ based on 35.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. Pair production of vector-like ${{\mathit t}^{\,'}}$ is seached for with one ${{\mathit t}^{\,'}}$ decaying into ${{\mathit Z}}{{\mathit t}}$ and the other ${{\mathit t}^{\,'}}$ decaying into ${{\mathit W}}{{\mathit b}}$, ${{\mathit Z}}{{\mathit t}}$, ${{\mathit h}}{{\mathit t}}$. Events with an opposite-sign lepton pair consistent with coming from ${{\mathit Z}}$ and jets are used. Mass limits are obtained for a variety of branching ratios of ${{\mathit t}^{\,'}}$.
22  SIRUNYAN 2019BW based on 35.9 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. The limit is for the pair-produced vector-like ${{\mathit t}^{\,'}}$ using all-hadronic final state. The analysis is made for the ${{\mathit W}}{{\mathit b}}$, ${{\mathit Z}}{{\mathit t}}$, ${{\mathit h}}{{\mathit t}}$ modes and mass limits are obtained for a variety of branching ratios.
23  AABOUD 2018CL based on 36.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. The limit is for the pair-produced vector-like ${{\mathit t}^{\,'}}$ using all-hadronic final state. The analysis is also made for the ${{\mathit W}}{{\mathit b}}$, ${{\mathit Z}}{{\mathit t}}$, ${{\mathit h}}{{\mathit t}}$ modes and mass limits are obtained for a variety of branching ratios.
24  AABOUD 2017L based on 36.1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 13 TeV. No signal is found in the search for heavy quark pair production that decay into ${{\mathit Z}}{{\mathit t}}$ followed by ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \nu}}{{\mathit \nu}}$ in the events with one lepton, large $\not E_T$, and ${}\geq{}$4 jets. The lower mass limit 0.87 (1.05) TeV is obtained for the singlet (doublet) model with other possible decay modes.
25  AAD 2015AR based on 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV. Used lepton-plus-jets final state. See Fig. 20 for mass limits in the plane of B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit H}}{{\mathit t}}$) vs. B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) from a combination of ${{\mathit t}^{\,'}}$ ${{\overline{\mathit t}}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}{+}$ ${{\mathit X}}$ and ${{\mathit t}^{\,'}}$ ${{\overline{\mathit t}}^{\,'}}$ $\rightarrow$ ${{\mathit H}}{{\mathit t}}{+}$ ${{\mathit X}}$ searches. Any branching ratio scenario is excluded for mass below 715 GeV.
26  AAD 2015BY based on 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV. Limit on pair-produced vector-like ${{\mathit t}^{\,'}}$ assuming the branching fractions to ${{\mathit W}}$, ${{\mathit Z}}$, and ${{\mathit h}}$ modes of the singlet model. Used events containing ${}\geq{}2{{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$2j (${}\geq{}$1 ${{\mathit b}}$) and including a same-sign lepton pair.
27  KHACHATRYAN 2015AI based on 19.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8 TeV. The search exploits all-hadronic final states by tagging boosted Higgs boson using jet substructure and ${{\mathit b}}$-tagging.
28  Based on 19.5 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 8TeV. The ${{\mathit t}^{\,'}}$ quark is pair produced and is assumed to decay into three different final states of , , and . The search is carried out using events with at least one isolated lepton.
29  Based on 4.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. No signal is found for the search of heavy quark pair production that decay into ${{\mathit W}}$ and a ${{\mathit b}}$ quark in the events with a high $p_T$ isolated lepton, large $\not E_T$ and at least 3 jets (${}\geq{}$ 1 ${{\mathit b}}$-tag). Vector-like quark of charge 2/3 with 400 $<$ ${\mathit m}_{{{\mathit t}^{\,'}}}$ $<$ 550 GeV and B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) $>$ 0.63 is excluded at 95$\%$ CL.
30  Based on 5.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. CHATRCHYAN 2013I looked for events with one isolated electron or muon, large $\not E_T$, and at least four jets with large transverse momenta, where one jet is likely to originate from the decay of a bottom quark.
31  Based on 1.04 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. No signal is found in the search for pair produced heavy quarks that decay into ${{\mathit W}}$ boson and a ${{\mathit b}}$ quark in the events with a high $p_T$ isolated lepton, large $\not E_T$ and at least 3 jets (${}\geq{}$1 ${{\mathit b}}$-tag).
32  Based on 5.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ data at $\sqrt {s }$ = 7 TeV. CHATRCHYAN 2012BC looked for ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production events with a single isolated high $p_T$ lepton, large $\not E_T$ and at least 4 high $p_T$ jets with a ${{\mathit b}}$-tag. The absence of signal above the SM background gives the limit for B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit W}}{{\mathit b}}$) = 1.
33  Based on 5.7 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at 1.96 TeV. AALTONEN 2011AH looked for ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production followed by ${{\mathit t}^{\,'}}$ decaying into a top quark and ${{\mathit X}}$, an invisible particle, in the all hadronic decay mode of ${{\mathit t}}{{\overline{\mathit t}}}$. No excess over the SM ${{\mathit t}}{{\overline{\mathit t}}}$ production gives the upper limit on ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production cross section as a function of ${\mathit m}_{{{\mathit t}^{\,'}}}$ and ${\mathit m}_{{{\mathit X}}}$. The result is obtained for B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit X}}{{\mathit t}}$) = 1.
34  Based on 5.6 fb${}^{-1}$ of data in ppbar collisions at 1.96 TeV. AALTONEN 2011AL looked for ${{\mathit \ell}}$ + ${}\geq{}$4j events and set upper limits on ${\mathit \sigma (}{{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}{)}$ as functions of ${\mathit m}_{{{\mathit t}^{\,'}}}$.
35  Based on 4.8 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at 1.96 TeV. AALTONEN 2011O looked for ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production signal when ${{\mathit t}^{\,'}}$ decays into a top quark and ${{\mathit X}}$, an invisible particle, in ${{\mathit \ell}}$ + $\not E_T$ + jets channel. No excess over the SM ${{\mathit t}}{{\overline{\mathit t}}}$ production gives the upper limit on ${{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}$ production cross section as a function of ${\mathit m}_{{{\mathit t}^{\,'}}}$ and ${\mathit m}_{{{\mathit X}}}$. The result is obtained for B( ${{\mathit t}^{\,'}}$ $\rightarrow$ ${{\mathit X}}{{\mathit t}}$) = 1.
36  Based on 5.3 fb${}^{-1}$ of data in ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at 1.96 TeV. ABAZOV 2011Q looked for ${{\mathit \ell}}$ + $\not E_T$ + ${}\geq{}$4j events and set upper limits on ${\mathit \sigma (}{{\mathit t}^{\,'}}{{\overline{\mathit t}}^{\,'}}{)}$ as functions of ${\mathit m}_{{{\mathit t}^{\,'}}}$.
37  Searches for pair production of a new heavy top-like quark ${{\mathit t}^{\,'}}$ decaying to a ${{\mathit W}}$ boson and another quark by fitting the observed spectrum of total transverse energy and reconstructed ${{\mathit t}^{\,'}}$ mass in the lepton + jets events.
38  HUANG 2008 reexamined the ${{\mathit t}^{\,'}}$ mass lower bound of 256 GeV obtained in AALTONEN 2008H that assumes B( ${{\mathit b}^{\,'}}$ $\rightarrow$ ${{\mathit q}}{{\mathit Z}}$) = 1 for ${{\mathit q}}$ = ${{\mathit u}}$, ${{\mathit c}}$ which does not hold when ${\mathit m}_{{{\mathit b}^{\,'}}}<{\mathit m}_{{{\mathit t}^{\,'}}}−{\mathit m}_{{{\mathit W}}}$ or the mixing sin$^2(\theta _{{{\mathit b}} {{\mathit t}^{\,'}}})$ is so tiny that the decay occurs outside of the vertex detector. Fig. 1 gives that lower bound on ${\mathit m}_{{{\mathit t}^{\,'}}}$ in the plane of sin$^2(\theta _{{{\mathit b}} {{\mathit t}^{\,'}}})$ and ${\mathit m}_{{{\mathit b}^{\,'}}}$.
References