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| CMS-PAS-TOP-17-007 | ||
| Measurement of the top quark mass with lepton+jets final states in pp collisions at $\sqrt{s}= $ 13 TeV | ||
| CMS Collaboration | ||
| September 2017 | ||
| Abstract: The mass of the top quark is measured using a sample of $\rm{t}\bar{\rm t}$ candidate events with one lepton, muon or electron, and at least four jets in the final state, collected by the CMS detector in pp collisions at $\sqrt{s}= $ 13 TeV at the CERN LHC. The candidate events are selected from data corresponding to an integrated luminosity of 35.9 fb$^{-1}$. For each event the mass is reconstructed from a kinematic fit of the decay products to a $\rm{t}\bar{\rm t}$ hypothesis. The top quark mass is determined simultaneously with an overall jet energy scale factor (JSF), constrained by the mass of the W boson in $\rm{q}\bar{\rm q}$ decays. The measurement is calibrated on samples simulated at next-to-leading order matched to parton shower. The top quark mass is found to be 172.25 $\pm$ 0.08 (stat+JSF) $\pm$ 0.62 (syst) GeV. The dependence of this result on event kinematical properties is studied and compared to predictions of different models of $\rm{t}\bar{\rm t}$ production. | ||
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Links:
CDS record (PDF) ;
inSPIRE record ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, EPJC 78 (2018) 891. The superseded preliminary plots can be found here. |
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| Figures & Tables | Summary | Additional Figures & Tables | References | CMS Publications |
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| Figures | |
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Figure 1:
(left) Invariant mass $m_\mathrm{W} ^\text {reco}$ of the two untagged jets and (right) the invariant mass $ {m_{\mathrm{t}}} ^\text {reco}$ of the two untagged jets and one of the b-tagged jets after the b tagging requirement. The vertical bars show the statistical uncertainty and the hatched bands show the statistical and systematic uncertainties considered in Sec. xxxxx added in quadrature. The lower portion of each panel show the ratio of the yields between the collision data and the simulation. The simulations are normalized to the luminosity. |
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Figure 1-a:
(left) Invariant mass $m_\mathrm{W} ^\text {reco}$ of the two untagged jets and (right) the invariant mass $ {m_{\mathrm{t}}} ^\text {reco}$ of the two untagged jets and one of the b-tagged jets after the b tagging requirement. The vertical bars show the statistical uncertainty and the hatched bands show the statistical and systematic uncertainties considered in Sec. xxxxx added in quadrature. The lower portion of each panel show the ratio of the yields between the collision data and the simulation. The simulations are normalized to the luminosity. |
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Figure 1-b:
(left) Invariant mass $m_\mathrm{W} ^\text {reco}$ of the two untagged jets and (right) the invariant mass $ {m_{\mathrm{t}}} ^\text {reco}$ of the two untagged jets and one of the b-tagged jets after the b tagging requirement. The vertical bars show the statistical uncertainty and the hatched bands show the statistical and systematic uncertainties considered in Sec. xxxxx added in quadrature. The lower portion of each panel show the ratio of the yields between the collision data and the simulation. The simulations are normalized to the luminosity. |
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Figure 2:
(left) The reconstructed W boson masses $m_\mathrm{W} ^\text {reco}$ and (right) the fitted top quark masses $ {m_{\mathrm{t}}} ^\text {fit}$ after the goodness-of-fit selection and the weighting by $P_\mathrm {gof}$. The vertical bars show the statistical uncertainty and the hatched bands show the statistical and systematic uncertainties added in quadrature. The lower portion of each panel shown the ratio of the yields between the collision data and the simulation. |
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Figure 2-a:
(left) The reconstructed W boson masses $m_\mathrm{W} ^\text {reco}$ and (right) the fitted top quark masses $ {m_{\mathrm{t}}} ^\text {fit}$ after the goodness-of-fit selection and the weighting by $P_\mathrm {gof}$. The vertical bars show the statistical uncertainty and the hatched bands show the statistical and systematic uncertainties added in quadrature. The lower portion of each panel shown the ratio of the yields between the collision data and the simulation. |
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Figure 2-b:
(left) The reconstructed W boson masses $m_\mathrm{W} ^\text {reco}$ and (right) the fitted top quark masses $ {m_{\mathrm{t}}} ^\text {fit}$ after the goodness-of-fit selection and the weighting by $P_\mathrm {gof}$. The vertical bars show the statistical uncertainty and the hatched bands show the statistical and systematic uncertainties added in quadrature. The lower portion of each panel shown the ratio of the yields between the collision data and the simulation. |
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Figure 3:
Mean difference between the calibrated and generated values of $ {m_{\mathrm{t}}} $ and JSF as a function of different generated $m_{\mathrm{t},\text {gen}}$ and five values of JSF for the muon channel (left) and the electron channel (right). The colored dashed lines correspond to straight line fits, the black solid line corresponds to a constant fit to all calibration points. The error bars indicate the statistical uncertainty on the mean difference. |
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Figure 3-a:
Mean difference between the calibrated and generated values of $ {m_{\mathrm{t}}} $ and JSF as a function of different generated $m_{\mathrm{t},\text {gen}}$ and five values of JSF for the muon channel (left) and the electron channel (right). The colored dashed lines correspond to straight line fits, the black solid line corresponds to a constant fit to all calibration points. The error bars indicate the statistical uncertainty on the mean difference. |
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Figure 3-b:
Mean difference between the calibrated and generated values of $ {m_{\mathrm{t}}} $ and JSF as a function of different generated $m_{\mathrm{t},\text {gen}}$ and five values of JSF for the muon channel (left) and the electron channel (right). The colored dashed lines correspond to straight line fits, the black solid line corresponds to a constant fit to all calibration points. The error bars indicate the statistical uncertainty on the mean difference. |
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Figure 4:
The likelihood ($-2 \Delta \log (\mathcal {L})$) for the 2D fit (left) and the hybrid fit (right) measured for the lepton+jets final state. The ellipses correspond to contours of $-2 \Delta \log (\mathcal {L}) = $ 1 (4, 9) allowing the construction one (two, three) $\sigma $ statistical intervals of $ {m_{\mathrm{t}}} $. |
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Figure 4-a:
The likelihood ($-2 \Delta \log (\mathcal {L})$) for the 2D fit (left) and the hybrid fit (right) measured for the lepton+jets final state. The ellipses correspond to contours of $-2 \Delta \log (\mathcal {L}) = $ 1 (4, 9) allowing the construction one (two, three) $\sigma $ statistical intervals of $ {m_{\mathrm{t}}} $. |
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Figure 4-b:
The likelihood ($-2 \Delta \log (\mathcal {L})$) for the 2D fit (left) and the hybrid fit (right) measured for the lepton+jets final state. The ellipses correspond to contours of $-2 \Delta \log (\mathcal {L}) = $ 1 (4, 9) allowing the construction one (two, three) $\sigma $ statistical intervals of $ {m_{\mathrm{t}}} $. |
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Figure 5:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 5-a:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 5-b:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 5-c:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 5-d:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 6:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 6-a:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 6-b:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 6-c:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 6-d:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the transverse momentum of the hadronically decaying top quark ($ {p_{\mathrm {T}}} ^{\rm {t,had}}$), the invariant mass of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($m_{{\mathrm{t} {}\mathrm{\bar{t}}}}$), the transverse momentum of the $ {\mathrm{t} {}\mathrm{\bar{t}}} $ system ($ {p_{\mathrm {T}}} ^{{\mathrm{t} {}\mathrm{\bar{t}}}}$), and the number of jets with $ {p_{\mathrm {T}}} > $ 30 GeV compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 7:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 7-a:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 7-b:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 7-c:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 7-d:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to different generator choices. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 8:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
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Figure 8-a:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 8-b:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 8-c:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
png pdf |
Figure 8-d:
Measurements of $ {m_{\mathrm{t}}} $ as a function of the $ {p_{\mathrm {T}}} $ of the b jet assigned to the hadronic decay branch ($ {p_{\mathrm {T}}} ^{\rm {b,had}}$), the pseudorapidity of the b jet assigned to the hadronic decay branch ($\left |\eta ^{\rm b,had}\right |$), the $\Delta R$ between the b jets ($\Delta R_{{\mathrm{b} \mathrm{\bar{b}}}}$), and the $\Delta R$ between the light quark jets ($\Delta R_{{\mathrm{q} \mathrm{\bar{q}}}}$) compared to alternative models of color reconnections. The filled circles represent the data, and the other symbols are for the simulations. For reasons of clarity the horizontal error bars are shown only for the data points and each of the simulations is shown as a single offset point with a vertical error bar representing its statistical uncertainty. The statistical uncertainty of the data is displayed by the inner error bars. For the outer error bars, the systematic uncertainties are added in quadrature. |
| Tables | |
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Table 1:
List of systematic uncertainties for the fit to the combined data set. |
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Table 2:
Observed shifts with respect to the default simulation for different models of color reconnection. |
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Table 3:
Observed shifts with respect to the default simulation for different generator setups. |
| Summary |
| The mass of the top quark has been measured with high precision by CMS in Run 1 of the CERN LHC. The most precise of these measurements is repeated using the 2016 data of Run 2 and POWHEG v2 interfaced to PYTHIA{}8 with the CUETP8M2T4 tune for the simulation. Candidate events are selected from $\sqrt{s}= $ 13 TeV data corresponding to an integrated luminosity of 35.9 fb$^{-1}$ requiring one lepton, muon or electron, and at least four jets with two b tags in the final state. The top quark mass is measured to be 172.25 $\pm$ 0.08 (stat+JSF) $\pm$ 0.62 (syst) GeV from the 161496 selected events. This result is consistent with the CMS measurements of Run 1 and no impact from the new reference generator or the change in the center-of-mass energy is observed. The top quark mass has also been studied as a function of the event kinematical properties. No indications of a kinematical bias in the measurements are observed. |
| Additional Figures | |
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Additional Figure 1:
CMS data [CMS-PAS-FSQ-15-007] at $\sqrt {s} = $ 13 TeV for particle densities of charged particles with $ {p_{\mathrm {T}}} > $ 0.5 GeV and $|\eta | < $ 0.8 in the transMIN region as defined by the leading charged particle, as a function of the transverse momentum of the leading charged-particle $p_{\textrm {T}}^{\textrm {max}}$. The data are compared to predictions of PYTHIA v8.226 Tune CUETP8M2T4, and of PYTHIA v8.226 with the two tunes using the QCD-inspired and gluon-move color reconnection models, respectively. The ratios of MC predictions to data are given below each panel. |
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Additional Figure 2:
CMS data [Phys. Lett. B 751 (2015)] at $\sqrt {s} = $ 13 TeV for the charged-particle pseudorapidity distribution, $\mathrm{d}N_{\textrm {ch}}/\mathrm{d}\eta $, in inelastic proton-proton collisions. The data are compared to predictions of PYTHIA v8.226 Tune CUETP8M2T4, and of PYTHIA v8.226 with the two tunes using the QCD-inspired and gluon-move color reconnection models, respectively. The ratios of MC predictions to data are given below each panel. |
| Additional Tables | |
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Additional Table 1:
The parameters obtained in the fits of the tunes of the PYTHIA v8.226 [Comput. Phys. Commun. 191 (2015)] event generator, based on the QCD-inspired [JHEP 08 (2015) 003] and the gluon-move [Eur. Phys. J. C 75 (2015)] color reconnection models, compared to the ones of the tune CUETP8M2T4 [CMS-PAS-TOP-16-021], using the MPI-based [Phys. Rev. D 36 (1987)] color reconnection model. The fits are performed by using both the Professor 1.4.0 software [Eur. Phys. J. C 65 (2010)] and RIVET 2.4.0 [Comput. Phys. Commun. 184 (2013)]. The observables used for extracting the tunes are the charged particle multiplicity and average ${p_{\mathrm {T}}}$ sum as a function of the leading charged-particle transverse momentum, $p_T^\textrm {max}$, measured by CMS at $\sqrt {s} = $ 13 TeV in transMIN and transMAX [CMS-PAS-FSQ-15-007], and the charged particle multiplcity as a function of pseudorapidity $\eta $, measured by CMS at $\sqrt {s} = $ 13 TeV [Phys. Lett. B 751 (2015)]. Likewise for the CUETP8M2T4 tune [CMS-PAS-TOP-16-021], the region between 0.5 $ < p_T^\textrm {max} < $ 3 GeV is excluded from the fit, since it is affected by possible contributions of diffractive processes, whose free parameters are not considered in the tuning procedure. Parameters marked with $^*$ are the ones which were kept fixed in the fit. For the QCD-inspired and gluon-move color reconnection models, the default values implemented in PYTHIA v8.226 are indicated in parentheses, where applicable. The goodness of fit divided by the number of degrees of freedom is also shown. |
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