CMS-PAS-B2G-19-005 | ||
A search for bottom-type, vector-like quark pair production in a fully hadronic mode in proton-proton collisions at √s= 13 TeV | ||
CMS Collaboration | ||
July 2020 | ||
Abstract: A search is described for the production of a pair of bottom-type vector-like quarks (VLQs), each decaying into a b quark and either a Higgs or a Z boson. The analysis is based on data from proton-proton collisions at a 13 TeV center-of-mass energy recorded by the CMS experiment, corresponding to a total integrated luminosity of 137 fb−1. Since the predominant decay modes of the Higgs and Z bosons are to a pair of quarks, the analysis focuses on final states consisting of jets resulting from the six quarks produced in the events. Because the two jets produced in the decay of a highly boosted Higgs or Z boson might merge to form a single jet, three independent analyses are performed, categorized by the number of observed jets. No signal in excess of the expected background is observed. Lower limits are set on the VLQ mass at the 95% confidence level, at 1570 GeV in the case where the VLQ decays exclusively to a b quark and a Higgs boson, 1390 GeV for when it decays exclusively to a b quark and a Z boson, and 1450 GeV for when it decays equally in these two modes. | ||
Links:
CDS record (PDF) ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, PRD 102 (2020) 112004. The superseded preliminary plots can be found here. |
Figures | |
![]() png pdf |
Figure 1:
Diagrams of the pair production of bottom-type VLQ quarks (B) that subsequently decay to a b or ˉb quark and either a Higgs or Z boson. In events targeted by this analysis, the Z boson then decays to a pair of quarks, where q denotes any quark other than a t quark, while the Higgs predominantly decays to b quarks. Upper left: bHbH mode, upper right: bHbZ mode, lower: bZbZ mode. |
![]() png pdf |
Figure 2:
Reconstructed VLQ mass distributions for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. Mass distributions for 4-jet (left), 5-jet (center), and 6-jet (right) events are shown for the three decay modes: bHbH (upper row), bHbZ (middle row), and bZbZ (lower row). |
![]() png |
Figure 2-a:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 4-jet events is shown for the bHbH decay mode. |
![]() png |
Figure 2-b:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 5-jet events is shown for the bHbH decay mode. |
![]() png |
Figure 2-c:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 6-jet events is shown for the bHbH decay mode. |
![]() png |
Figure 2-d:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 4-jet events is shown for the bHbZ decay mode. |
![]() png |
Figure 2-e:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 5-jet events is shown for the bHbZ decay mode. |
![]() png |
Figure 2-f:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 6-jet events is shown for the bHbZ decay mode. |
![]() png |
Figure 2-g:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 4-jet events is shown for the bZbZ decay mode. |
![]() png |
Figure 2-h:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 5-jet events is shown for the bZbZ decay mode. |
![]() png |
Figure 2-i:
Reconstructed VLQ mass distribution for simulated signal events with a generated VLQ mass mB= 1200 GeV. A moderate requirement of χ2mod/ndf< 2 is applied to the events. The mass distribution for 6-jet events is shown for the bZbZ decay mode. |
![]() png pdf |
Figure 3:
Distribution of χ2mod for the best jet combination for simulated 1200 GeV VLQ events (red histogram) and data (black points), for 4-jet events (left), 5-jet events (center), and 6-jet events (right). The simulated signal events and data events are normalized to the same value within the displayed χ2mod range. |
![]() png |
Figure 3-a:
Distribution of χ2mod for the best jet combination for simulated 1200 GeV VLQ events (red histogram) and data (black points), for 4-jet events. The simulated signal events and data events are normalized to the same value within the displayed χ2mod range. |
![]() png |
Figure 3-b:
Distribution of χ2mod for the best jet combination for simulated 1200 GeV VLQ events (red histogram) and data (black points), for 5-jet events. The simulated signal events and data events are normalized to the same value within the displayed χ2mod range. |
![]() png |
Figure 3-c:
Distribution of χ2mod for the best jet combination for simulated 1200 GeV VLQ events (red histogram) and data (black points), for 6-jet events. The simulated signal events and data events are normalized to the same value within the displayed χ2mod range. |
![]() png pdf |
Figure 4:
Distributions of the average reconstructed mass of VLQ candidates for the jet combination with the least χ2 in 4-jet (left), 5-jet (center), and 6-jet (right) multiplicity events. The red lines show the exponential fit in the range 1000-2000 GeV. The lower panels show the fractional difference, (data-fit)/fit. |
![]() png |
Figure 4-a:
Distributions of the average reconstructed mass of VLQ candidates for the jet combination with the least χ2 in 4-jet multiplicity events. The red lines show the exponential fit in the range 1000-2000 GeV. The lower panels show the fractional difference, (data-fit)/fit. |
![]() png |
Figure 4-b:
Distributions of the average reconstructed mass of VLQ candidates for the jet combination with the least χ2 in 5-jet multiplicity events. The red lines show the exponential fit in the range 1000-2000 GeV. The lower panels show the fractional difference, (data-fit)/fit. |
![]() png |
Figure 4-c:
Distributions of the average reconstructed mass of VLQ candidates for the jet combination with the least χ2 in 6-jet multiplicity events. The red lines show the exponential fit in the range 1000-2000 GeV. The lower panels show the fractional difference, (data-fit)/fit. |
![]() png pdf |
Figure 5:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 4-jet (left column), 5-jet (center column), and 6-jet (right column) multiplicities, and for the bHbH (upper row), bHbZ (middle row), and bZbZ (lower row) event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-a:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 4-jet multiplicities, and for the bHbH event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-b:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 5-jet multiplicities, and for the bHbH event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-c:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 6-jet multiplicities, and for the bHbH event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-d:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 4-jet multiplicities, and for the bHbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-e:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 5-jet multiplicities, and for the bHbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-f:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 6-jet multiplicities, and for the bHbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-g:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 4-jet multiplicities, and for the bZbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-h:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 5-jet multiplicities, and for the bZbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 5-i:
Dependence of the BJTF on the average reconstructed VLQ mass in the control region 12 <χ2mod/ndf< 48, for 6-jet multiplicities, and for the bZbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png pdf |
Figure 6:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 4-jet (left column), 5-jet (center column), and 6-jet (right column) multiplicities, and for the bHbH (upper row), bHbZ (middle row), and bZbZ (lower row) event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-a:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 4-jet ultiplicities, and for the bHbH event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-b:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 5-jet multiplicities, and for the bHbH event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-c:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 6-jet multiplicities, and for the bHbH event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-d:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 4-jet multiplicities, and for the bHbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-e:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 5-jet multiplicities, and for the bHbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-f:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 6-jet multiplicities, and for the bHbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-g:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 4-jet multiplicities, and for the bZbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-h:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 5-jet multiplicities, and for the bZbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png |
Figure 6-i:
Dependence of the BJTF on χ2mod/ndf in the low-mass VLQ region, for 6-jet multiplicities, and for the bZbZ event modes. The data is shown in black points, and the linear fit and its uncertainty are shown as the red line and the pale red band. |
![]() png pdf |
Figure 7:
The reduction factor in data events, for 4-jet (left column), 5-jet (center column), and 6-jet (right column) multiplicities, and for the bHbH (upper row), bHbZ (middle row), and bZbZ (lower row) event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-a:
The reduction factor in data events, for 4-jet multiplicities, and for the bHbH event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-b:
The reduction factor in data events, for 5-jet multiplicities, and for the bHbH event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-c:
The reduction factor in data events, for 6-jet multiplicities, and for the bHbH event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-d:
The reduction factor in data events, for 4-jet multiplicities, and for the bHbZ event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-e:
The reduction factor in data events, for 5-jet multiplicities, and for the bHbZ event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-f:
The reduction factor in data events, for 6-jet multiplicities, and for the bHbZ event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-g:
The reduction factor in data events, for 4-jet multiplicities, and for the bZbZ event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-h:
The reduction factor in data events, for 5-jet multiplicities, and for the bZbZ event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png |
Figure 7-i:
The reduction factor in data events, for 6-jet multiplicities, and for the bZbZ event modes. The red box indicates the signal region, which is excluded from these plots. |
![]() png pdf |
Figure 8:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 4-jet (left column), 5-jet (center column), and 6-jet (right column) multiplicities, and for the bHbH (upper row), bHbZ (middle row), and bZbZ (lower row) event modes. The red box indicates the signal region. |
![]() png |
Figure 8-a:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 4-jet multiplicities, and for the bHbH event modes. The red box indicates the signal region. |
![]() png |
Figure 8-b:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 5-jet multiplicities, and for the bHbH event modes. The red box indicates the signal region. |
![]() png |
Figure 8-c:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 6-jet multiplicities, and for the bHbH event modes. The red box indicates the signal region. |
![]() png |
Figure 8-d:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 4-jet multiplicities, and for the bHbZ event modes. The red box indicates the signal region. |
![]() png |
Figure 8-e:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 5-jet multiplicities, and for the bHbZ event modes. The red box indicates the signal region. |
![]() png |
Figure 8-f:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 6-jet multiplicities, and for the bHbZ event modes. The red box indicates the signal region. |
![]() png |
Figure 8-g:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 4-jet multiplicities, and for the bZbZ event modes. The red box indicates the signal region. |
![]() png |
Figure 8-h:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 5-jet multiplicities, and for the bZbZ event modes. The red box indicates the signal region. |
![]() png |
Figure 8-i:
The reduction factor in simulated VLQ signal events with mB= 1200 GeV, for 6-jet multiplicities, and for the bZbZ event modes. The red box indicates the signal region. |
![]() png pdf |
Figure 9:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines). Left column: 4-jet events, center column: 5-jet events, right column: 6-jet events; upper row: bHbH, middle row: bHbZ, lower row: bZbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-a:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 4-jet events; bHbH. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-b:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 5-jet events; bHbH. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-c:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 6-jet events; bHbH. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-d:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 4-jet events; bHbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-e:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 5-jet events; bHbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-f:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 6-jet events; bHbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-g:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 4-jet events; bZbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-h:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 5-jet events; bZbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png |
Figure 9-i:
Data (black points), expected background (solid blue histogram), and expected background plus a VLQ signal for different VLQ masses (colored lines); 6-jet events; bZbZ. For the signal, a 100% B→bH branching fraction is assumed. The hatched regions for the background and background plus signal distributions indicate the systematic uncertainties. All three data-taking years are combined. |
![]() png pdf |
Figure 10:
Expected limits on the VLQ mass at 95% CL as a function of the branching fractions B(B→bH) and B(B→bZ). |
![]() png pdf |
Figure 11:
Observed limits on the VLQ mass at 95% CL as a function of the branching fractions B(B→bH) and B(B→bZ). |
![]() png |
Figure 12-a:
The 95% confidence limit on the cross section for VLQ pair production as a function of VLQ mass for the B(B→bH)= 100% branching fraction hypothesis. The solid black line indicates the observed limit and the dashed line indicates the expected limit with 1 sigma (green band) and 2 sigma (yellow band) uncertainties. The theoretical cross section and its uncertainty are shown as the red line and pale red band. |
![]() png |
Figure 12-b:
The 95% confidence limit on the cross section for VLQ pair production as a function of VLQ mass for the B(B→bZ)= 100% branching fraction hypothesis. The solid black line indicates the observed limit and the dashed line indicates the expected limit with 1 sigma (green band) and 2 sigma (yellow band) uncertainties. The theoretical cross section and its uncertainty are shown as the red line and pale red band. |
![]() png |
Figure 12-c:
The 95% confidence limit on the cross section for VLQ pair production as a function of VLQ mass for the B(B→bH)=B(B→bZ)= 50% branching fraction hypothesis. The solid black line indicates the observed limit and the dashed line indicates the expected limit with 1 sigma (green band) and 2 sigma (yellow band) uncertainties. The theoretical cross section and its uncertainty are shown as the red line and pale red band. |
Tables | |
![]() png pdf |
Table 1:
Measured values of the trigger efficiencies for events with HT> 1350 GeV. The uncertainties are statistical only. |
![]() png pdf |
Table 2:
Efficiency of the offline HT selection for each of the jet multiplicity channels, for three VLQ masses (1000, 1200, and 1400 GeV). The efficiency is the fraction of events in each jet multiplicity category meeting the HT> 1350 GeV cut. |
![]() png pdf |
Table 3:
Values of the BJTF for data events with VLQ mass candidates in the range of 500 to 800 GeV for each of the three event modes and three jet multiplicities. |
![]() png pdf |
Table 4:
Systematic uncertainties common to all three event modes and all three jet multiplicities. |
![]() png pdf |
Table 5:
Systematic uncertainties for each event mode and jet multiplicity. The reported values indicate the uncertainty in the event yield in a ±75 GeV window about the signal peak for a generated signal mass mB= 1600 GeV. |
![]() png pdf |
Table 6:
Optimized values of the χ2mod/ndf selection as a function of jet multiplicity and event mode. |
Summary |
This note describes a search for bottom-type, vector-like quark (VLQ) pair production based on data collected by the CMS detector in 2016--2018 at √s= 13 TeV, where the VLQ B decays into a b quark and either a Higgs boson H or a Z boson. The analysis targets the fully hadronic B→bH and B→bZ decays by tagging each jet and using a modified χ2 metric to reconstruct the event. Different jet multiplicity categories were used to account for the fact that Higgs or Z boson decays can produce either two distinct jets or, if boosted, a single merged jet. Backgrounds were estimated using data from a low VLQ mass region and extrapolated into the signal region using a modified χ2 control region. Limits were set on the VLQ mass at 95% confidence level as a function of the branching fractions for B→bH and B→bZ. Previous limits [15,16] on the B mass have been increased from 1010 GeV to 1570 GeV in the 100% B→bH case, from 1070 GeV to 1390 GeV in the 100% B→bZ case, and from 1025 GeV to 1450 GeV in the 50% B→bH and 50% B→bZ case. |
References | ||||
1 | G. 't Hooft | Naturalness, chiral symmetry, and spontaneous chiral symmetry breaking | NATO Sci. Ser. B 59 (1980) 135 | |
2 | J. Wess and B. Zumino | A Lagrangian model invariant under supergauge transformations | PLB 49 (1974) 52 | |
3 | P. Fayet and S. Ferrara | Supersymmetry | PR 32 (1977) 249 | |
4 | H. Georgi and A. Pais | Calculability and naturalness in gauge theories | PRD 10 (1974) 539 | |
5 | D. B. Kaplan, H. Georgi, and S. Dimopoulos | Composite Higgs scalars | PLB 136 (1984) 187 | |
6 | K. Agashe, R. Contino, and A. Pomarol | The minimal composite Higgs model | NPB 719 (2005) 165 | hep-ph/0412089 |
7 | N. Arkani-Hamed, A. G. Cohen, and H. Georgi | Electroweak symmetry breaking from dimensional deconstruction | PLB 513 (2001) 232 | hep-ph/0105239 |
8 | N. Arkani-Hamed, A. G. Cohen, E. Katz, and A. E. Nelson | The littlest Higgs | JHEP 07 (2002) 034 | hep-ph/0206021 |
9 | F. del Aguila and M. J. Bowick | The possibility of new fermions with ΔI= 0 mass | NPB 224 (1983) 107 | |
10 | J. A. Aguilar-Saavedra, R. Benbrik, S. Heinemeyer, and M. P\'erez-Victoria | Handbook of vectorlike quarks: Mixing and single production | PRD 88 (2013) 094010 | 1306.0572 |
11 | F. del Aguila, M. Perez-Victoria, and J. Santiago | Observable contributions of new exotic quarks to quark mixing | JHEP 09 (2000) 011 | hep-ph/0007316 |
12 | J. A. Aguilar-Saavedra | Mixing with vector-like quarks: constraints and expectations | EPJ Web Conf. 60 (2013) 16012 | 1306.4432 |
13 | A. Atre, M. Carena, T. Han, and J. Santiago | Heavy quarks above the top at the Tevatron | PRD 79 (2009) 054018 | 0806.3966 |
14 | A. Atre et al. | Model-independent searches for new quarks at the LHC | JHEP 08 (2011) 080 | 1102.1987 |
15 | ATLAS Collaboration | Search for pair production of heavy vector-like quarks decaying into hadronic final states in pp collisions at √s= 13 TeV with the ATLAS detector | PRD 98 (2018) 092005 | 1808.01771 |
16 | CMS Collaboration | Search for pair production of vectorlike quarks in the fully hadronic final state | PRD 100 (2019) 072001 | CMS-B2G-18-005 1906.11903 |
17 | ATLAS Collaboration | Combination of the searches for pair-produced vector-like partners of the third-generation quarks at √s= 13 TeV with the ATLAS detector | PRL 121 (2018) 211801 | 1808.02343 |
18 | The ATLAS Collaboration, The CMS Collaboration, The LHC Higgs Combination Group | Procedure for the LHC Higgs boson search combination in Summer 2011 | CMS-NOTE-2011-005 | |
19 | CMS Collaboration | The CMS trigger system | JINST 12 (2017) P01020 | CMS-TRG-12-001 1609.02366 |
20 | CMS Collaboration | The CMS experiment at the CERN LHC | JINST 3 (2008) S08004 | CMS-00-001 |
21 | NNPDF Collaboration | Parton distributions for the LHC Run II | JHEP 04 (2015) 040 | 1410.8849 |
22 | T. Sjostrand et al. | An introduction to PYTHIA 8.2 | CPC 191 (2015) 159 | 1410.3012 |
23 | CMS Collaboration | Event generator tunes obtained from underlying event and multiparton scattering measurements | EPJC 76 (2016) 155 | CMS-GEN-14-001 1512.00815 |
24 | CMS Collaboration | Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements | EPJC 80 (2020) 4 | CMS-GEN-17-001 1903.12179 |
25 | M. Czakon, P. Fiedler, and A. Mitov | Total top-quark pair-production cross section at hadron colliders through O(α4S) | PRL 110 (2013) 252004 | 1303.6254 |
26 | M. R. Whalley, D. Bourilkov, and R. C. Group | The Les Houches accord PDFs (LHAPDF) and LHAGLUE | in HERA and the LHC: A workshop on the implications of HERA for LHC physics. Proceedings, Part B, p. 575 2005 | hep-ph/0508110 |
27 | CMS Collaboration | Search for vector-like T and B quark pairs in final states with leptons at √s= 13 TeV | JHEP 08 (2018) 177 | CMS-B2G-17-011 1805.04758 |
28 | GEANT4 Collaboration | GEANT4--a simulation toolkit | NIMA 506 (2003) 250 | |
29 | J. Allison et al. | Geant4 developments and applications | IEEE Trans. Nucl. Sci. 53 (2006) 270 | |
30 | CMS Collaboration | Particle-flow reconstruction and global event description with the CMS detector | JINST 12 (2017) P10003 | CMS-PRF-14-001 1706.04965 |
31 | M. Cacciari, G. P. Salam, and G. Soyez | The anti-kt jet clustering algorithm | JHEP 04 (2008) 063 | 0802.1189 |
32 | M. Cacciari, G. P. Salam, and G. Soyez | FastJet user manual | EPJC 72 (2012) 1896 | 1111.6097 |
33 | D. Bertolini, P. Harris, M. Low, and N. Tran | Pileup per particle identification | JHEP 10 (2014) 059 | 1407.6013 |
34 | CMS Collaboration | Jet algorithms performance in 13 TeV data | CMS-PAS-JME-16-003 | CMS-PAS-JME-16-003 |
35 | CMS Collaboration | Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV | JINST 12 (2017) P02014 | CMS-JME-13-004 1607.03663 |
36 | Y. L. Dokshitzer, G. D. Leder, S. Moretti, and B. R. Webber | Better jet clustering algorithms | JHEP 08 (1997) 001 | hep-ph/9707323 |
37 | M. Wobisch and T. Wengler | Hadronization corrections to jet cross-sections in deep inelastic scattering | in Proceedings of the Workshop on Monte Carlo Generators for HERA Physics, Hamburg, Germany, p. 270 1998 | hep-ph/9907280 |
38 | M. Dasgupta, A. Fregoso, S. Marzani, and G. P. Salam | Towards an understanding of jet substructure | JHEP 09 (2013) 029 | 1307.0007 |
39 | J. M. Butterworth, A. R. Davison, M. Rubin, and G. P. Salam | Jet substructure as a new Higgs search channel at the LHC | PRL 100 (2008) 242001 | 0802.2470 |
40 | A. J. Larkoski, S. Marzani, G. Soyez, and J. Thaler | Soft drop | JHEP 05 (2014) 146 | 1402.2657 |
41 | CMS Collaboration | Performance of heavy flavour identification algorithms in proton-proton collisions at 13 TeV at the CMS experiment | CDS | |
42 | CMS Collaboration | Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV | JINST 13 (2018) P05011 | CMS-BTV-16-002 1712.07158 |
43 | CMS Collaboration | CMS luminosity measurement for the 2016 data taking period | CMS-PAS-LUM-17-001 | CMS-PAS-LUM-17-001 |
44 | CMS Collaboration | CMS luminosity measurement for the 2017 data-taking period at √s= 13 TeV | CMS-PAS-LUM-17-004 | CMS-PAS-LUM-17-004 |
45 | CMS Collaboration | CMS luminosity measurement for the 2018 data-taking period at √s= 13 TeV | CMS-PAS-LUM-18-002 | CMS-PAS-LUM-18-002 |
46 | J. Butterworth et al. | PDF4LHC recommendations for LHC Run II | JPG 43 (2016) 023001 | 1510.03865 |
47 | A. L. Read | Presentation of search results: The CLs technique | JPG 28 (2002) 2693 | |
48 | T. Junk | Confidence level computation for combining searches with small statistics | NIMA 434 (1999) 435 | hep-ex/9902006 |
49 | G. Cowan, K. Cranmer, E. Gross, and O. Vitells | Asymptotic formulae for likelihood-based tests of new physics | EPJC 71 (2011) 1554 | 1007.1727 |
![]() |
Compact Muon Solenoid LHC, CERN |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |