The cross section for ttbar production in the alljets final state is measured in pp collisions at a centreofmass energy of 8 TeV at the LHC with the CMS detector, in data corresponding to an integrated luminosity of 18.4/fb. The inclusive cross section is found to be 275.6 ± 6.1 (stat) ± 37.8 (syst) ± 7.2 (lumi) pb. The normalized differential cross sections are measured as a function of the top quark transverse momenta, p_{T}, and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark p_{T} spectra are significantly softer than theoretical predictions.
The paper is available on the arXiv:1509.06076.
Figure 1: Distribution of the reconstructed top quark mass after the kinematic fit. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panel shows the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 
Figure 2a: Distribution of the kinematic fit probability. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 2b: Distribution of the distance between the reconstructed b partons at the etaphi plane. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 
Figure 3a: Distribution of the p_{T} of the leading jet. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 3b: Distribution of the p_{T} of the second leading jet. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 3c: Distribution of the p_{T} of the third leading jet. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 3d: Distribution of the p_{T} of the fourth leading jet. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 3e: Distribution of the p_{T} of the fifth leading jet. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 3f: Distribution of the p_{T} of the sixth leading jet. The normalization of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 
Figure 4a: Distribution of the leading reconstructed top quark p_{T} . The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 4b: Distribution of the subleading reconstructed top quark p_{T}. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 
Figure 5a: Distribution of the p_{T} of the reconstructed top quark pair. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 5b: Distribution of the rapidity of the reconstructed top quark pair. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 
Figure 6a: Distribution of the reconstructed top quark mass after the kinematic fit in the bin 0150 GeV of the leading reconstructed top quark p_{T}. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 6b: Distribution of the reconstructed top quark mass after the kinematic fit in the bin 150225 GeV of the leading reconstructed top quark p_{T}. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 6c: Distribution of the reconstructed top quark mass after the kinematic fit in the bin 225300 GeV of the leading reconstructed top quark p_{T}. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 6d: Distribution of the reconstructed top quark mass after the kinematic fit in the bin 300375 GeV of the leading reconstructed top quark p_{T}. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 

Figure 6e: Distribution of the reconstructed top quark mass after the kinematic fit in the bin 375500 GeV of the leading reconstructed top quark p_{T}. The normalizations of the ttbar signal and the QCD multijet background are taken from the template fit to the data. The bottom panels show the fractional difference between the data and the sum of signal and background predictions, with the shaded band representing the MC statistical uncertainty. PDF  PNG 
Figure 7a: Normalized fiducial differential cross section of the ttbar production as a function of the leading reconstructed top quark p_{T} (detector level). The bottom panels show the fractional difference between various MC predictions and the data. Statistical uncertainties are shown with error bars, and systematic uncertainties with the shaded band. PDF  PNG 

Figure 7b: Normalized fiducial differential cross section of the ttbar production as a function of the subleading reconstructed top quark p_{T} (detector level). The bottom panels show the fractional difference between various MC predictions and the data. Statistical uncertainties are shown with error bars, and systematic uncertainties with the shaded band. PDF  PNG 
Figure 8a: Normalized differential cross section of the ttbar production at parton level as a function of the leading top quark p_{T}. The bottom panels show the fractional difference between various MC predictions and the data. Statistical uncertainties are shown with error bars, while theoretical (theo.) and experimental (exp.) systematic uncertainties with the shaded bands. PDF  PNG 

Figure 8b: Normalized differential cross section of the ttbar production at parton level as a function of the subleading top quark p_{T}. The bottom panels show the fractional difference between various MC predictions and the data. Statistical uncertainties are shown with error bars, while theoretical (theo.) and experimental (exp.) systematic uncertainties with the shaded bands. PDF  PNG 
Figure 9a: Normalized differential cross section of the ttbar production at particle level as a function of the leading top quark p_{T}. The bottom panels show the fractional difference between various MC predictions and the data. Statistical uncertainties are shown with error bars, while theoretical (theo.) and experimental (exp.) systematic uncertainties with the shaded bands. PDF  PNG 

Figure 9b: Normalized differential cross section of the ttbar production at particle level as a function of the subleading top quark p_{T}. The bottom panels show the fractional difference between various MC predictions and the data. Statistical uncertainties are shown with error bars, while theoretical (theo.) and experimental (exp.) systematic uncertainties with the shaded bands. PDF  PNG 
Ratio of data over theory (Madgraph interfaced with Pythia 6) for the normalized differential cross section of the ttbar production at parton level as a function of the leading top p_{T} in different decay channels. The error bars represent the total uncertainty. The measurements in the leptonic final states are taken from arXiv:1505.04480. PDF  PNG 

Ratio of data over theory (Madgraph interfaced with Pythia 6) for the normalized differential cross section of the ttbar production at parton level as a function of the subleading top p_{T} in different decay channels. The error bars represent the total uncertainty. The measurements in the leptonic final states are taken from arXiv:1505.04480. PDF  PNG 
Fractional uncertainties in the inclusive ttbar production cross section. PDF  PNG 

Normalized differential ttbar cross section as a function of the p_{T} of the leading (p_{T}^{(1)}) and subleading (p_{T}^{(2)}) top quarks or antiquarks. The results are presented at detector level in the visible phase space. PDF  PNG 

Normalized differential ttbar cross section as a function of the p_{T} of the leading (p_{T}^{(1)}) and subleading (p_{T}^{(2)}) top quarks or antiquarks. The results are presented at parton level in the full phase space. PDF  PNG 

Normalized differential ttbar cross section as a function of the p_{T} of the leading (p_{T}^{(1)}) and subleading (p_{T}^{(2)}) top quarks or antiquarks. The results are presented at particle level. PDF  PNG 
 AndreasMeyer  20150910