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| CMS-PAS-B2G-19-004 | ||
| Search for single production of a vector-like quark T decaying to a top quark and a Z boson with the Z boson decaying to neutrinos | ||
| CMS Collaboration | ||
| March 2021 | ||
| Abstract: A search is presented for single production of a vector-like quark T of electric charge +2/3 in the decay channel featuring a top quark and a Z boson, with the top quark decaying hadronically and the Z boson decaying to neutrinos. The search uses data collected by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV recorded at the CERN LHC in 2016-2018, corresponding to an integrated luminosity of 136 fb$^{-1}$. The search is sensitive to a T quark mass between 0.6 and 1.8 TeV with decay widths ranging from narrow up to 30% of the T quark mass. Reconstruction strategies for the top quark are optimized for boosted and non-boosted regimes. At the 95% confidence level, the product of the cross section and branching fraction is excluded above values in the range 18-210 fb in the studied T quark mass and width ranges. | ||
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Links:
CDS record (PDF) ;
inSPIRE record ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, Submitted to JHEP. The superseded preliminary plots can be found here. |
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| Figures | |
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Figure 1:
Representative leading-order Feynman diagram for the production of single vector-like quark T decaying a Z boson and a top quark. |
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Figure 2:
Distributions of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with no forward jet (upper) and at least one forward jet (lower) and for 2016 (left), 2017 (center), and 2018 (right). The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 2-a:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with no forward jet, for 2016. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 2-b:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with no forward jet, for 2017. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 2-c:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with no forward jet, for 2018. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 2-d:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with at least one forward jet, for 2016. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 2-e:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with at least one forward jet, for 2017. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 2-f:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the merged categories but with the AK8 jet SD mass outside the interval 105-220 GeV, for events with at least one forward jet, for 2018. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown after the fit to data in the control regions. |
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Figure 3:
Distributions of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with no forward jet (upper) and at least one forward jet (lower) and for 2016 (left), 2017 (center), and 2018 (right). The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
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Figure 3-a:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with no forward jet, for 2016. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
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Figure 3-b:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with no forward jet, for 2017. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
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Figure 3-c:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with no forward jet, for 2018. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
png pdf |
Figure 3-d:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with at least one forward jet, for 2016. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
png pdf |
Figure 3-e:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with at least one forward jet, for 2017. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
png pdf |
Figure 3-f:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for events in test samples selected as in the resolved categories but without the requirement of at least one b jet in the event, for events with at least one forward jet, for 2018. The predictions of the main background components have been determined in simulation with scale factors applied to match data as extracted from control regions, and the uncertainties are shown before the fit to data. |
png pdf |
Figure 4:
Distributions of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with no forward jet (upper) and at least one forward jet (lower), for 2016 (left), 2017 (center), and 2018 (right). The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 4-a:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with no forward jet, for 2016. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 4-b:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with no forward jet, for 2017. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 4-c:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with no forward jet, for 2018. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 4-d:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with at least one forward jet, for 2016. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 4-e:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with at least one forward jet, for 2017. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 4-f:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the merged categories, for events with at least one forward jet, for 2018. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5:
Distributions of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with no forward jet (upper) and at least one forward jet (lower), for 2016 (left), 2017 (center), and 2018 (right). The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5-a:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with no forward jet, for 2016. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5-b:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with no forward jet, for 2017. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5-c:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with no forward jet, for 2018. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5-d:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with at least one forward jet, for 2016. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5-e:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with at least one forward jet, for 2017. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 5-f:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the partially merged categories, for events with at least one forward jet, for 2018. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6:
Distributions of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with no forward jet (upper) and at least one forward jet (lower), for 2016 (left), 2017 (center), and 2018 (right). The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6-a:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with no forward, for 2016. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6-b:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with no forward, for 2017. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6-c:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with no forward, for 2018. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6-d:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with at least one forward, for 2016. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6-e:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with at least one forward, for 2017. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 6-f:
Distribution of the transverse mass ${M_{\mathrm {T}}}$ of the reconstructed top quark and ${{\vec{p}}_{\mathrm {T}}^{\,\text {miss}}}$ system for the selected events in the resolved categories, for events with at least one forward, for 2018. The distributions for the main background components have been determined in simulation with scale factors extracted from control regions. All background processes and the respective uncertainties are derived from the fit to data, while the distributions of signal processes are represented according to the expectation before the fit. Signal yields are multiplied by a factor 100 to improve their visibility. |
png pdf |
Figure 7:
Observed and expected 95% CL upper limits on the product of the single T quark production cross section and the $ {\mathrm {T}} \to \mathrm{t} \mathrm{Z} $ branching fraction as a function of the T mass for a narrow width resonance (upper left), and a width of 10% (upper right), 20% (lower left), and 30% (lower right) of the T mass. A singlet T quark is assumed, which is produced in association with a bottom quark. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The continuous curves show the theoretical expectation at NLO. In the case of a narrow width resonance, width of 1% (5%) of the resonance mass is reported with a red (blue) curve. |
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Figure 7-a:
Observed and expected 95% CL upper limits on the product of the single T quark production cross section and the $ {\mathrm {T}} \to \mathrm{t} \mathrm{Z} $ branching fraction as a function of the T mass for a narrow width resonance. A singlet T quark is assumed, which is produced in association with a bottom quark. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The continuous curves show the theoretical expectation at NLO. Width of 1% (5%) of the resonance mass is reported with a red (blue) curve. |
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Figure 7-b:
Observed and expected 95% CL upper limits on the product of the single T quark production cross section and the $ {\mathrm {T}} \to \mathrm{t} \mathrm{Z} $ branching fraction as a function of the T mass for a width of 10% of the T mass. A singlet T quark is assumed, which is produced in association with a bottom quark. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The continuous curves show the theoretical expectation at NLO. |
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Figure 7-c:
Observed and expected 95% CL upper limits on the product of the single T quark production cross section and the $ {\mathrm {T}} \to \mathrm{t} \mathrm{Z} $ branching fraction as a function of the T mass for a width of 20% of the T mass. A singlet T quark is assumed, which is produced in association with a bottom quark. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The continuous curves show the theoretical expectation at NLO. |
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Figure 7-d:
Observed and expected 95% CL upper limits on the product of the single T quark production cross section and the $ {\mathrm {T}} \to \mathrm{t} \mathrm{Z} $ branching fraction as a function of the T mass for a width of 30% of the T mass. A singlet T quark is assumed, which is produced in association with a bottom quark. The inner (green) band and the outer (yellow) band indicate the regions containing 68 and 95%, respectively, of the distribution of limits expected under the background-only hypothesis. The continuous curves show the theoretical expectation at NLO. |
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Figure 8:
Observed 95% CL upper limit on the product of the single T quark production cross section and the $ {\mathrm {T}} \to \mathrm{t} \mathrm{Z} $ branching fraction as a function of the T mass for widths of 10%, 20%, and 30% of the T mass. A singlet T quark is assumed, which is produced in association with a bottom quark. The solid red line indicates the boundary of the excluded region (on the hatched side) of theoretical cross sections as reported in Table 2. |
| Tables | |
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Table 1:
Theoretical production cross sections for single production of a T quark in association with a bottom quark with $\Gamma /m_ {\mathrm {T}} =$ 1% and 5%. The framework for the computation is described in Refs. [49,50]. |
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Table 2:
Theoretical production cross sections for single production of a T quark in association with a bottom quark with $\Gamma /m_ {\mathrm {T}} = $ 10%. The framework for the computation is described in Ref. [49,50]. |
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Table 3:
Selection efficiencies $\epsilon _{{\mathrm {T}}}$ of the $ {\mathrm {T}} \to {\mathrm{t} \mathrm{Z}} $ signal in each of the event categories defined in the analysis. The efficiencies are reported for three hypotheses on the mass $m_{{\mathrm {T}}}$ and three hypotheses on the width $\Gamma _{{\mathrm {T}}}$ of the T quark. The statistical uncertainties on the efficiency estimates are also reported. |
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Table 4:
Summary of the systematic uncertainties. The maximum range of change in the pre-fit event yield of signals and backgrounds across all years and categories for one standard deviation change of the systematic effect is reported in the "Effects'' column. The third column reports whether a systematic uncertainty is considered fully correlated or not across the years of data taking. The fourth column indicates whether the uncertainty affects both the yield and the shape of the distributions or the yield only. Except for the background scale factors, all the uncertainties affect both signal and background inputs to the fit. |
| Summary |
| A search for the single production of a vector-like quark T with electric charge $+$2/3 decaying to a top and a Z boson has been presented with LHC proton-proton collision data collected by the CMS experiment and corresponding to an integrated luminosity of 136 fb$^{-1}$. Upper limits at the 95% confidence level were set on the product of the production cross section and the $ \mathrm{T} \to {\mathrm{t}\mathrm{Z}} $ channel branching fraction. Values greater than 210-18 fb for masses in the range 0.6-1.8 TeV were excluded at the 95% confidence level for a T quark of negligible resonance width produced in association with a bottom quark. Interpretation of these results using a theoretical framework in which the T quark is a singlet, and assuming a 5% fractional width of the resonance, led to the exclusion of a T quark of mass below 0.98 TeV. The excluded mass range extends up to 1.4 TeV for higher hypotheses of the resonance width. These results provide the current best published limits on single vector-like quarks production. |
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