CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

CMS-TOP-17-006 ; ATLAS-TOPQ-2017-16 ; CERN-EP-2019-005
Combinations of single-top-quark production cross-section measurements and ${|f_{\mathrm LV}{V_{\mathrm{tb}}} |} $ determinations at $\sqrt{s} =$ 7 and 8 TeV with the ATLAS and CMS experiments
JHEP 05 (2019) 088
Abstract: This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at at $\sqrt{s} =$ 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb$^{-1}$ at $\sqrt{s} =$ 7 TeV, and 12.2 to 20.3 fb$^{-1}$ at $\sqrt{s} =$ 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: $t$-channel , tW, and $s$-channel . The combined $t$-channel cross-sections are 67.5 $\pm$ 5.7 pb and 87.7 $\pm$ 5.8 pb at $\sqrt{s} =$ 7 and 8 TeV respectively. The combined qW cross-sections are 16.3 $\pm$ 4.1 pb and 23.1 $\pm$ 3.6 pb at $\sqrt{s} =$ 7 and 8 TeV respectively. For the $s$-channel \ cross-section, the combination yields 4.9 $\pm$ 1.4 pb at $\sqrt{s} =$ 8 TeV. The square of the magnitude of the CKM matrix element ${V_{\mathrm{tb}}} $ multiplied by a model-independent form factor $ {f_{\rm LV}} $ is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation $|{V_{{\mathrm{td}}}} |,|{V_{{\mathrm{ts}}}} | \ll |{V_{\mathrm{tb}}} |$. All the $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ determinations, extracted from individual ratios at $\sqrt{s} =$ 7 and 8 TeV, are combined, resulting in ${|{f_{\rm LV}} {V_{\mathrm{tb}}} |} = $ 1.02 $\pm$ 0.04 (meas) $\pm$ 0.02 (theo). All combinations are consistent with their corresponding Standard Model predictions.
Figures & Tables Summary Additional Figures References CMS Publications
Figures

png pdf
Figure 1:
Representative Feynman diagrams at LO in QCD and in the five-flavour-number scheme for single-top-quark production in (left) the $t$-channel, (middle) tW production, and (right) the $s$-channel.

png pdf
Figure 1-a:
Representative Feynman diagram at LO in QCD and in the five-flavour-number scheme for single-top-quark production in the $t$-channel.

png pdf
Figure 1-b:
Representative Feynman diagram at LO in QCD and in the five-flavour-number scheme for single-top-quark production in tW production.

png pdf
Figure 1-c:
Representative Feynman diagram at LO in QCD and in the five-flavour-number scheme for single-top-quark production in the $s$-channel.

png pdf
Figure 2:
Single-top-quark cross-section measurements performed by ATLAS and CMS, together with the combined results. These measurements are compared with the theoretical predictions at NLO and NLO+NNLL for all three production modes and the prediction at NNLO for $t$-channel only. The corresponding theoretical uncertainties are also presented. The scale uncertainty for the NNLO prediction is small and is presented as a narrow band under the dashed line.

png pdf
Figure 3:
Correlation matrix of the overall $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ combination. Each bin corresponds to a measurement in a given production mode, experiment, and at a given centre-of-mass energy.

png pdf
Figure 4:
The combined $| {f_{\rm LV}} {V_{\mathrm{tb}} }| $ value extracted from the $t$-channel and tW cross-section measurements at $ \sqrt{s} = $ 7 and 8 TeV from ATLAS and CMS, as well as the ATLAS $s$-channel measurement at $ \sqrt{s} = $ 8 TeV, is shown together with the combined $| {f_{\rm LV}} {V_{\mathrm{tb}} }| $ values for each production mode. The theoretical predictions for $t$-channel and $s$-channel production are computed at NLO accuracy, while the theoretical predictions for tW are calculated at NLO+NNLL accuracy. The $ \sigma_{\text{teo}} $ uncertainties used to compute $| {f_{\rm LV}} {V_{\mathrm{tb}} }| $ include scale, PDF+$ \alpha_{\text{s}} $, $ m_{\mathrm{t}} $, and $ E_{\text{beam}} $ variations.

png pdf
Figure 5:
Results of the stability tests performed by varying of the correlation assumptions in different uncertainty categories: theory modelling (scales and radiation modelling, NLO matching, and PS and hadronisation), JES, dominant theoretical cross-section predictions (i.e. PDF+$ \alpha_{\text{s}} $ and scale) and integrated luminosity. Two or three variations are considered depending on the uncertainty category. The corresponding relative shifts (with shift = varied - nominal) in the central value, $ \Delta| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 / | {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $, and in its uncertainty, $ \Delta(\delta | {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 )/(\delta | {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $), are shown.
Tables

png pdf
Table 1:
Predicted cross-sections for single-top-quark production at $ \sqrt{s} = $ 7 and 8 TeV at the LHC. Uncertainties include scale and PDF+$ \alpha_{\text{s}} $ variations, except for the NNLO predictions, which only contain the scale variation. The PDF+$ \alpha_{\text{s}} $ uncertainties are evaluated according to the PDF4LHC prescription only for the NLO predictions. The uncertainties associated with the top-quark mass $ m_{\mathrm{t}} $ and beam energy $ E_{\text{beam}} $ are also given for the NLO predictions for the $t$- and $s$-channels, and for the NLO+NNLL prediction for tW production. The value of $ m_{\mathrm{t}} $ is set to 172.5 GeV in all predictions. The cross-sections marked with $\dagger$ are those used in the ${f_{\rm LV}} {V_{\mathrm{tb}} }$ combination.

png pdf
Table 2:
Summary of the single-top-quark cross-section measurements published by the ATLAS and CMS Collaborations at $ \sqrt{s} = $ 7 and 8 TeV. Total uncertainties are shown. Small differences between the integrated luminosity values in different analyses within the same experiment and centre-of-mass energy are due to different luminosity calibrations at the time of publication.

png pdf
Table 3-a:
Contribution from each uncertainty category to the combined $t$-channel cross-section ($ \sigma_{\text{t-chan.}} $) uncertainty at (a) $ \sqrt{s} = $ 7 TeV. The total uncertainty is computed by adding in quadrature all the individual systematic uncertainties (including the uncertainty in the integrated luminosity) and the statistical uncertainty in data.

png pdf
Table 3-b:
Contribution from each uncertainty category to the combined $t$-channel cross-section ($ \sigma_{\text{t-chan.}} $) uncertainty at (a) $ \sqrt{s} = $ 8 TeV. The total uncertainty is computed by adding in quadrature all the individual systematic uncertainties (including the uncertainty in the integrated luminosity) and the statistical uncertainty in data.

png pdf
Table 4-a:
Contribution from each uncertainty category to the combined tW cross-section ($ \sigma_{\mathrm{tW}} $) uncertainty at (a) $ \sqrt{s} = $ 7 TeV. The total uncertainty is computed by adding in quadrature all the individual systematic uncertainties (including the uncertainty in the integrated luminosity) and the statistical uncertainty in data.

png pdf
Table 4-b:
Contribution from each uncertainty category to the combined tW cross-section ($ \sigma_{\mathrm{tW}} $) uncertainty at (a) $ \sqrt{s} = $ 8 TeV. The total uncertainty is computed by adding in quadrature all the individual systematic uncertainties (including the uncertainty in the integrated luminosity) and the statistical uncertainty in data.

png pdf
Table 5:
Contribution from each uncertainty category to the combined $s$-channel cross-section ($ \sigma_{\text{s-chan.}} $) uncertainty at $ \sqrt{s} = $ 8 TeV. The total uncertainty is computed by adding in quadrature all the individual systematic uncertainties (including the uncertainty in the integrated luminosity) and the statistical uncertainty in data.

png pdf
Table 6:
Results of the ATLAS and CMS individual $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ determinations that are the inputs to the overall $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ combination together with their experimental uncertainties. The values of $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ may slightly differ from those published for the different analyses since in this paper the theoretical cross-sections used are those marked with $ \dagger $ in Table 1. Experimental uncertainties contributing less than 1% are denoted by $<$0.01. Entries with - mean that this uncertainty was not evaluated for this analysis.

png pdf
Table 7:
Contributions from each experimental and theoretical uncertainty category to the overall $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ combination. The total uncertainty is computed by adding in quadrature all of the individual systematic uncertainties (including the integrated luminosity and theoretical cross-section) and the statistical uncertainty in data.

png pdf
Table 8:
BLUE weights for the overall $| {f_{\rm LV}} {V_{\mathrm{tb}} }|^2 $ combination.

png pdf
Table 9:
Measured cross-sections, uncertainty components, their magnitudes (relative to the individual measurements) and the correlation ($\rho$) between the ATLAS and CMS $ \sigma_{\text{t-chan.}} $ measurements at $ \sqrt{s} = $ 7 TeV. Uncertainties in the same row can be compared between experiments, as detailed in the text. The naming conventions follow those of the corresponding experiments.

png pdf
Table 10:
Measured cross-sections, uncertainty components, their magnitudes (relative to the individual measurements) and the correlation ($\rho$) between the ATLAS and CMS $ \sigma_{\text{t-chan.}} $ measurements at $ \sqrt{s} = $ 8 TeV. Uncertainties in the same row can be compared between experiments, as detailed in the text. The naming conventions follow those of the corresponding experiments.

png pdf
Table 11:
Measured cross-sections, uncertainty components, their magnitudes (relative to the individual measurements) and the correlation ($\rho$) between the ATLAS and CMS $ \sigma_{\mathrm{tW}} $ measurements at $ \sqrt{s} = $ 7 TeV. Uncertainties in the same row can be compared between experiments, as detailed in the text. The naming conventions follow those of the corresponding experiments.

png pdf
Table 12:
Measured cross-sections, uncertainty components, their magnitudes (relative to the individual measurements) and the correlation ($\rho$) between the ATLAS and CMS $ \sigma_{\mathrm{tW}} $ measurements at $ \sqrt{s} = $ 8 TeV. Uncertainties in the same row can be compared between experiments, as detailed in the text. The naming conventions follow those of the corresponding experiments.

png pdf
Table 13:
Measured cross-sections, uncertainty components, their magnitudes (relative to the individual measurements) and the correlation ($\rho$) between the ATLAS and CMS $ \sigma_{\text{s-chan.}} $ measurements at $ \sqrt{s} = $ 8 TeV. Uncertainties in the same row can be compared between experiments, as detailed in the text. The naming conventions follow those of the corresponding experiments.
Summary
The combinations of single-top-quark production cross-section measurements in the $t$-channel, tW, and $s$-channel production modes are presented, using data from LHC pp collisions collected by the ATLAS and CMS Collaborations. The combinations for each production mode are performed at $ \sqrt{s} = $ 7 and 8 TeV, using data corresponding to integrated luminosities of 1.17 to 5.1 fb${-1}$ at $ \sqrt{s} = $ 7 TeV, and of 12.2 to 20.3 fb${-1}$ at $ \sqrt{s} = $ 8 TeV. The combined $t$-channel cross-sections are found to be 67.5 $\pm$ 5.7 pb and 87.7 $\pm$ 5.8 pb at $ \sqrt{s} = $ 7 and 8 TeV respectively. The values of the combined tW cross-sections at 740 $ \sqrt{s} = $ 7 and 8 TeV are 16.3 $\pm$ 4.1 pb and 23.1 $\pm$ 3.6 pb respectively. For the $s$-channel cross-section, the combination yields 4.9 $\pm$ 1.4 pb at $ \sqrt{s} = $ 8 TeV. The square of the magnitude of the CKM matrix element $V_{\mathrm{tb}}$ multiplied by a form factor accounting for possible contributions from physics beyond the SM, $ f_{\rm LV} $, is determined from each production mode at each centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction, and assuming that the top-quark-related CKM matrix elements obey the relation $|V_{\mathrm{td}} |$, $|V_{\mathrm{ts}} | \ll |V_{\mathrm{tb}} |$. The values of $| f_{\rm LV} V_{\mathrm{tb}} |^2$ extracted from individual ratios at $ \sqrt{s} = $ 7 and 8 TeV yield a combined value of $| f_{\rm LV} V_{\mathrm{tb}} | = $ 1.02 $\pm$ 0.04 (meas) $\pm$ 0.02 (theo). All combined measurements are consistent with their corresponding SM predictions.
Additional Figures

png pdf
Additional Figure 1:
Single-top-quark cross-section measurements performed by ATLAS and CMS, together with the combined results. These measurements are compared with the theoretical predictions at NLO and NLO+NNLL for all three production modes and the prediction at NNLO for $t$-channel only. The corresponding theoretical uncertainties are also presented. The scale uncertainty for the NNLO prediction is small and is presented as a narrow band under the dashed line.
References
1 CDF Collaboration Observation of Electroweak Single Top-Quark Production Phys. Rev. Lett. 103 (2009) 092002 0903.0885
2 D0 Collaboration Observation of Single Top Quark Production Phys. Rev. Lett. 103 (2009) 092001 0903.0850
3 A. Giammanco and R. Schwienhorst Single top-quark production at the Tevatron and the LHC Rev. Mod. Phys. 90 (2018) 035001 1710.10699
4 T. M. P. Tait and C.-P. Yuan Single top quark production as a window to physics beyond the standard model Phys. Rev. D 63 (2000) 014018 hep-ph/0007298
5 Q.-H. Cao, J. Wudka and C.-P. Yuan Search for new physics via single-top production at the LHC Phys. Lett. B 658 (2007) 50 0704.2809
6 R. M. Godbole, L. Hartgring, I. Niessen and C. D. White Top polarisation studies in Ht and Wt production JHEP 01 (2012) 011 1111.0759
7 C. Zhang and S. Willenbrock Effective-field-theory approach to top-quark production and decay Phys. Rev. D 83 (2011) 034006 1008.3869
8 J. A. Aguilar-Saavedra Single top quark production at LHC with anomalous Wtb couplings Nucl. Phys. B 804 (2008) 160 0803.3810
9 J. A. Dror, M. Farina, E. Salvioni and J. Serra Strong tW scattering at the LHC JHEP 01 (2016) 071 1511.03674
10 M. S. Berger, V. A. Kostelecy and Z. Liu Lorentz and CPT violation in top-quark production and decay Phys. Rev. D 93 (2016) 036005 1509.08929
11 H.-J. He, T. M. P. Tait and C.-P. Yuan New top-flavor models with seesaw mechanism Phys. Rev. D 62 (2000) 011702 hep-ph/9911266
12 J. Aguilar-Saavedra, R. Benbrik, S. Heinemeyer and M. Perez-Victoria Handbook of vectorlike quarks: Mixing and single production Phys. Rev. D 88 (2013) 094010 1306.0572
13 G. Durieux, F. Maltoni and C. Zhang Global approach to top-quark flavor-changing interactions Phys. Rev. D 91 (2015) 074017 1412.7166
14 J. W. Nutter, R. Schwienhorst, D. G. E. Walker and J.-H. Yu Single top production as a probe of $B^0$ quarks Phys. Rev. D 86 (2012) 094006 1207.5179
15 M. Hashemi Observability of heavy charged Higgs through $s$-channel single top events at LHC JHEP 11 (2013) 005 1310.5209
16 E. Drueke et al. Single top production as a probe of heavy resonances, Phys. Rev. D 91 (2015) 054020 1409.7607
17 N. Cabibbo Unitary Symmetry and Leptonic Decays, Phys. Rev. Lett. 10 (1963) 531
18 M. Kobayashi and T. Maskawa CP-Violation in the Renormalizable Theory of Weak Interaction, Prog. Theor. Phys. 49 (1973) 652
19 M. Tanabashi et al. Review of Particle Physics Phys. Rev. D 98 (2018) 030001
20 D0 Collaboration Precision Measurement of the Ratio $\mathcal{B}( t \to Wb)/ \mathcal{B}( t \to Wq)$ and Extraction Phys. Rev. Lett. 107 (2011) 121802 1106.5436
21 CDF Collaboration Measurement of $R = \mathcal{B}( t \to Wb)/ \mathcal{B}( t \to Wq)$ in top-quark-pair decays Phys. Rev. D 87 (2013) 111101 1303.6142
22 CDF Collaboration Measurement of $\mathcal{B}( t \to Wb)/ \mathcal{B}( t \to Wq)$ in Top-Quark-Pair Decays Using Phys. Rev. Lett. 112 (2014) 221801 1404.3392
23 CMS Collaboration Measurement of the ratio $\mathcal{B}( t \to Wb)/ \mathcal{B}( t \to Wq)$ in pp collisions at $ \sqrt{s} = $ 8 TeV Phys. Lett. B 736 (2014) 33 CMS-TOP-12-035
1404.2292
24 J. A. Aguilar-Saavedra A minimal set of top anomalous couplings Nucl. Phys. B 812 (2009) 181 0811.3842
25 D0 Collaboration Combination of searches for anomalous top quark couplings with 5.4 fb$^{-1}$ of $p\bar{p}$ collisions Phys. Lett. B 713 (2012) 165 1204.2332
26 J. Alwall et al. Is $V_{\mathrm{tb}} \simeq 1$? Eur. Phys. J. C 49 (2007) 791 hep-ph/0607115
27 T. M. P. Tait tW-mode of single top production Phys. Rev. D 61 (1999) 034001 hep-ph/9909352
28 A. Belyaev and E. Boos Single top quark tW+X production at the CERN LHC: A closer look Phys. Rev. D 63 (2001) 034012 hep-ph/0003260
29 Q.-H. Cao and B. Yan Determining $V_{\mathrm{tb}} $ at electron-positron colliders Phys. Rev. D 92 (2015) 094018 1507.06204
30 CDF and D0 Collaborations Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element $V_{\mathrm{tb}}$ Phys. Rev. Lett. 115 (2015) 152003 1503.05027
31 R. Frederix, E. Re and P. Torrielli Single-top t-channel hadroproduction in the four-flavour scheme with POWHEG and aMC@NLO JHEP 09 (2012) 130 1207.5391
32 ATLAS Collaboration Fiducial, total and differential cross-section measurements of t-channel single top-quark production in pp collisions at 8 TeV using data collected by the ATLAS detector Eur. Phys. J. C 77 (2017) 531 1702.02859
33 CMS Collaboration Measurement of the t-channel single-top-quark production cross section and of the $|V_{\mathrm{tb}} |$ CKM matrix element in pp collisions at $ \sqrt{s} = $ 8 TeV JHEP 06 (2014) 090 CMS-TOP-12-038
1403.7366
34 ATLAS Collaboration Measurement of the production cross-section of a single top quark in association with a W boson at 8 TeV with the ATLAS experiment JHEP 01 (2016) 064 1510.03752
35 CMS Collaboration Observation of the Associated Production of a Single Top Quark and a W Boson in pp Collisions at $ \sqrt{s} = $ 8 TeV Phys. Rev. Lett. 112 (2014) 231802 CMS-TOP-12-040
1401.2942
36 CDF and D0 Collaborations Observation of s-Channel Production of Single Top Quarks at the Tevatron Phys. Rev. Lett. 112 (2014) 231803 1402.5126
37 ATLAS Collaboration Evidence for single top-quark production in the $s$-channel in proton-proton collisions at $ \sqrt{s} = $ 8 TeV with the ATLAS detector using the Matrix Element Method Phys. Lett. B 756 (2016) 228 1511.05980
38 M. Aliev et al. HATHOR - HAdronic Top and Heavy quarks crOss section calculatoR Comput. Phys. Commun. 182 (2011) 1034 1007.1327
39 P. Kant et al. HATHOR for single top-quark production: Updated predictions and uncertainty estimates for single top-quark production in hadronic collisions Comput. Phys. Commun. 191 (2015) 74 1406.4403
40 A. D. Martin,W. J. Stirling, R. S. Thorne and G.Watt, Uncertainties on S in global PDF analyses and implications for predicted hadronic cross sections Eur. Phys. J. C 64 (2009) 653 0905.3531
41 A. D. Martin, W. J. Stirling, R. S. Thorne and G. Watt Parton distributions for the LHC Eur. Phys. J. C 63 (2009) 189 0901.0002
42 M. Botje et al. The PDF4LHCWorking Group Interim Recommendations, 2011 1101.0538
43 H.-L. Lai et al. New parton distributions for collider physics Phys. Rev. D 82 (2010) 074024 1007.2241
44 R. D. Ball et al. Parton distributions with LHC data Nucl. Phys. B 867 (2013) 244 1207.1303
45 N. Kidonakis NNLL threshold resummation for top-pair and single-top production Phys. Part. Nucl. 45 (2014) 714 1210.7813
46 N. Kidonakis Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production Phys. Rev. D 83 (2011) 091503 1103.2792
47 N. Kidonakis Two-loop soft anomalous dimensions for single top quark associated production with a $W^{-}$ or $H^{-}$ Phys. Rev. D 82 (2010) 054018 1005.4451
48 N. Kidonakis Next-to-next-to-leading logarithm resummation for s-channel single top quark production Phys. Rev. D 81 (2010) 054028 1001.5034
49 M. Brucherseifer, F. Caola and K. Melnikov On the NNLO QCD corrections to single-top production at the LHC Phys. Lett. B 736 (2014) 58 1404.7116
50 S. S. D. Willenbrock and D. A. Dicus Production of heavy quarks from W-gluon fusion Phys. Rev. D 34 (1986) 155
51 N. Kidonakis, Top Quark Production Proceedings, Helmholtz International Summer School on Physics of Heavy Quarks and Hadrons (HQ 2013) JINR 2013 1311.0283
52 F. Demartin, B. Maier, F. Maltoni, K. Mawatari and M. Zaro tWH associated production at the LHC Eur. Phys. J. C 77 (2017) 34 1607.05862
53 J. M. Campbell and F. Tramontano Next-to-leading order corrections to Wt production and decay Nucl. Phys. B 726 (2005) 109 hep-ph/0506289
54 M. Czakon, P. Fiedler and A. Mitov Total Top-Quark Pair-Production Cross Section at Hadron Colliders Through $\mathcal{O}(\alpha_{s}^4)$ Phys. Rev. Lett. 110 (2013) 252004 1303.6254
55 U. Langenfeld, S. Moch and P. Uwer New results for $t\bar{t}$ production at hadron colliders Proceedings, 17th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2009): Madrid 2009 0907.2527
56 E. Todesco and J. Wenninger Large Hadron Collider momentum calibration and accuracy Phys. Rev. Accel. Beams 20 (2017) 081003
57 ATLAS Collaboration Comprehensive measurements of t-channel single top-quark production cross sections at $ \sqrt{s} = $ 7 TeV with the ATLAS detector Phys. Rev. D 90 (2014) 112006 1406.7844
58 CMS Collaboration Measurement of the single-top-quark t-channel cross section in pp collisions at $ \sqrt{s} = $ 7 TeV JHEP 12 (2012) 035 CMS-TOP-11-021
1209.4533
59 ATLAS Collaboration Evidence for the associated production of a W boson and a top quark in ATLAS at $ \sqrt{s} = $ 7 TeV Phys. Lett. B 716 (2012) 142 1205.5764
60 CMS Collaboration Evidence for Associated Production of a Single Top Quark and W Boson in pp Collisions at $ \sqrt{s} = $ 7 TeV Phys. Rev. Lett. 110 (2013) 022003 CMS-TOP-11-022
1209.3489
61 CMS Collaboration Search for s channel single top quark production in pp collisions at $ \sqrt{s} = $ 7 and 8 TeV JHEP 09 (2016) 027 CMS-TOP-13-009
1603.02555
62 Y. Freund and R. E. Schapire A Decision-Theoretic Generalization of On-Line Learning and an Application to Boosting J. Comput. Syst. Sci. 55 (1997) 119
63 J. H. Friedman Recent Advances in Predictive (Machine) Learning J. Classif. 23 (2006) 175
64 A. Hoecker et al. TMVA - Toolkit for Multivariate Data Analysis, 2007 physics/0703039
65 M. Feindt and U. Kerzel The NeuroBayes neural network package Nucl. Instrum. Meth. A 559 (2006) 190
66 K. Kondo Dynamical Likelihood Method for Reconstruction of Events With Missing Momentum. 1: Method and Toy Models J. Phys. Soc. Jap. 57 (1988) 4126
67 K. Kondo Dynamical Likelihood Method for Reconstruction of Events With Missing Momentum. 2: Mass Spectra for 2!2 Processes J. Phys. Soc. Jap. 60 (1991) 836
68 P. Nason A new method for combining NLO QCD with shower Monte Carlo algorithms JHEP 11 (2004) 040 hep-ph/0409146
69 S. Frixione, P. Nason and C. Oleari Matching NLO QCD computations with parton shower simulations: the POWHEG method JHEP 11 (2007) 070 0709.2092
70 S. Alioli, P. Nason, C. Oleari and E. Re NLO single-top production matched with shower in POWHEG: s- and t-channel contributions JHEP 09 (2009) 111, [Erratum: JHEP 02 (2010) 011] 0907.4076
71 S. Alioli, P. Nason, C. Oleari and E. Re A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX JHEP 06 (2010) 043 1002.2581
72 E. Re Single-top Wt-channel production matched with parton showers using the POWHEG method Eur. Phys. J. C 71 (2011) 1547 1009.2450
73 J. Alwall, M. Herquet, F. Maltoni, O. Mattelaer and T. Stelzer MadGraph 5: going beyond JHEP 06 (2011) 128 1106.0522
74 T. Sjostrand, S. Mrenna and P. Z. Skands Pythia 6.4 physics and manual JHEP 05 (2006) 026 hep-ph/0603175
75 L. Lyons, D. Gibaut and P. Clifford How to combine correlated estimates of a single physical quantity Nucl. Instrum. Meth. A 270 (1988) 110
76 A. Valassi Combining correlated measurements of several different physical quantities Nucl. Instrum. Meth. A 500 (2003) 391
77 R. Nisius On the combination of correlated estimates of a physics observable Eur. Phys. J. C 74 (2014) 3004 1402.4016
78 L. Lista The bias of the unbiased estimator: A study of the iterative application of the BLUE method Nucl. Instrum. Meth. A 764 (2014) 82, [Erratum: Nucl. Instrum. Meth. A 773 (2015) 87] 1405.3425
79 A. Valassi and R. Chierici Information and treatment of unknown correlations in the combination of measurements using the BLUE method Eur. Phys. J. C 74 (2014) 2717 1307.4003
80 ATLAS Collaboration Improved luminosity determination in pp collisions at $ \sqrt{s} = $ 7 TeV using the ATLAS detector at the LHC Eur. Phys. J. C 73 (2013) 2518 1302.4393
81 ATLAS Collaboration Luminosity determination in pp collisions at $ \sqrt{s} = $ 8 TeV using the ATLAS detector at the LHC Eur. Phys. J. C 76 (2016) 653 1608.03953
82 CMS Collaboration Absolute Calibration of the Luminosity Measurement at CMS: Winter 2012 Update CDS
83 CMS Collaboration CMS Luminosity Based on Pixel Cluster Counting -- Summer 2013 Update CDS
84 S. van der Meer Calibration of the effective beam height in the ISR CERN-ISR-PO-68-31, 1968
85 ATLAS Collaboration Measurement of $t\bar{t}$ production with a veto on additional central jet activity in pp collisions at $ \sqrt{s} = $ 7 TeV using the ATLAS detector Eur. Phys. J. C 72 (2012) 2043 1203.5015
86 ATLAS Collaboration Comparison of Monte Carlo generator predictions for gap fraction and jet multiplicity observables in $t\bar{t}$ events ATL-PHYS-PUB-2014-005, 2014
87 M. L. Mangano, F. Piccinini, A. D. Polosa, M. Moretti and R. Pittau ALPGEN, a generator for hard multiparton processes in hadronic collisions JHEP 07 (2003) 001 hep-ph/0206293
88 T. Gleisberg et al. Event generation with SHERPA 1.1 JHEP 02 (2009) 007 0811.4622
89 S. Frixione and B. R. Webber Matching NLO QCD computations and parton shower simulations JHEP 06 (2002) 029 hep-ph/0204244
90 P. Z. Skands Tuning Monte Carlo generators: The Perugia tunes Phys. Rev. D 82 (2010) 074018 1005.3457
91 J. Alwall et al. The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations JHEP 07 (2014) 079 1405.0301
92 G. Corcella et al. Herwig 6: an event generator for hadron emission reactions with interfering gluons (including supersymmetric processes) JHEP 01 (2001) 010 hep-ph/0011363
93 J. M. Butterworth, J. R. Forshaw and M. H. Seymour Multiparton interactions in photoproduction at HERA Z. Phys. C 72 (1996) 637 hep-ph/9601371
94 E. Boos et al. CompHEP 4.4 -- automatic computations from Lagrangians to events Nucl. Instrum. Meth. A 534 (2004) 250 hep-ph/0403113
95 A. Pukhov et al. CompHEP -- a package for evaluation of Feynman diagrams and integration over multi-particle phase space, 1999 hep-ph/9908288
96 ATLAS Collaboration Jet energy measurement with the ATLAS detector in proton-proton collisions at $ \sqrt{s} = $ 7 TeV Eur. Phys. J. C 73 (2013) 2304 1112.6426
97 ATLAS Collaboration Jet energy measurement and its systematic uncertainty in proton-proton collisions at $ \sqrt{s} = $ 7 TeV with the ATLAS detector Eur. Phys. J. C 75 (2015) 17 1406.0076
98 CMS Collaboration Determination of jet energy calibration and transverse momentum resolution in CMS JINST 6 (2011) P11002 CMS-JME-10-011
1107.4277
99 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
100 ATLAS Collaboration Performance of b-jet identification in the ATLAS experiment JINST 11 (2016) P04008 1512.01094
101 ATLAS Collaboration Calibration of b-tagging using dileptonic top pair events in a combinatorial likelihood approach with the ATLAS experiment ATLAS-CONF-2014-004, 2014
102 ATLAS Collaboration Calibration of the performance of b-tagging for c and light-flavour jets in the 2012 ATLAS data ATLAS-CONF-2014-046, 2014
103 CMS Collaboration Identification of b-quark jets with the CMS experiment JINST 8 (2013) P04013 CMS-BTV-12-001
1211.4462
104 CMS Collaboration Performance of b tagging at $ \sqrt{s} = $ 8 TeV in multijet, $t\bar{t}$ and boosted topology events CDS
105 M. L. Mangano, M. Moretti, F. Piccinini and M. Treccani Matching matrix elements and shower evolution for top-pair production in hadronic collisions JHEP 01 (2007) 013 hep-ph/0611129
106 S. Alekhin et al. The PDF4LHC Working Group Interim Report, (2011) 1101.0536
107 J. Butterworth et al. PDF4LHC recommendations for LHC Run II J. Phys. G 43 (2016) 023001 1510.03865
108 S. Frixione, E. Laenen, P. Motylinski, C. D. White and B. R. Webber Single-top hadroproduction in association with a W boson JHEP 07 (2008) 029 0805.3067
109 A. S. Belyaev, E. E. Boos and L. V. Dudko Single top quark at future hadron colliders: Complete signal and background study Phys. Rev. D 59 (1999) 075001 hep-ph/9806332
110 C. D. White, S. Frixione, E. Laenen and F. Maltoni Isolating Wt production at the LHC JHEP 11 (2009) 074 0908.0631
111 CMS Collaboration Measurement of the differential cross section for top quark pair production in pp collisions at $ \sqrt{s} = $ 8 TeV Eur. Phys. J. C 75 (2015) 542 CMS-TOP-12-028
1505.04480
112 M. Czakon, P. Fiedler, D. Heymes and A. Mitov NNLO QCD predictions for fully-differential top-quark pair production at the Tevatron JHEP 05 (2016) 034 1601.05375
113 ATLAS Collaboration Measurements of top-quark pair differential cross-sections in the lepton+jets channel in pp collisions at $ \sqrt{s} = $ 8 TeV using the ATLAS detector Eur. Phys. J. C 76 (2016) 538 1511.04716
114 ATLAS and CMS Collaborations Jet energy scale uncertainty correlations between ATLAS and CMS ATL-PHYS-PUB-2014-020, CMS-PAS-JME-14-003, 2014
115 ATLAS and CMS Collaborations Jet energy scale uncertainty correlations between ATLAS and CMS at $ \sqrt{s} = $ 8 TeV ATL-PHYS-PUB-2015-049, CMS-PAS-JME-15-001, 2015
116 ATLAS Collaboration Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton-proton collision data Eur. Phys. J. C 74 (2014) 3130 1407.3935
117 ATLAS Collaboration Electron and photon energy calibration with the ATLAS detector using LHC Run 1 data Eur. Phys. J. C 74 (2014) 3071 1407.5063
118 ATLAS Collaboration Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton-proton collision data Eur. Phys. J. C 74 (2014) 2941 1404.2240
119 ATLAS Collaboration Electron efficiency measurements with the ATLAS detector using 2012 LHC proton-proton collision data Eur. Phys. J. C 77 (2017) 195 1612.01456
120 CMS Collaboration Particle-flow reconstruction and global event description with the CMS detector JINST 12 (2017) P10003 CMS-PRF-14-001
1706.04965
121 ATLAS Collaboration Performance of algorithms that reconstruct missing transverse momentum in $ \sqrt{s} = $ 8 TeV proton-proton collisions in the ATLAS detector Eur. Phys. J. C 77 (2017) 241 1609.09324
122 CMS Collaboration Performance of the CMS missing transverse momentum reconstruction in pp data at $ \sqrt{s} = $ 8 TeV JINST 10 (2015) P02006 CMS-JME-13-003
1411.0511
123 R. J. Barlow and C. Beeston Fitting using finite Monte Carlo samples Comput. Phys. Commun. 77 (1993) 219
124 ATLAS Collaboration Comparison of Monte Carlo generator predictions to ATLAS measurements of top pair production at 7 TeV ATL-PHYS-PUB-2015-002, 2015
125 ATLAS Collaboration ATLAS Computing Acknowledgements ATL-GEN-PUB-2016-002
Compact Muon Solenoid
LHC, CERN