Combination of inclusive top-quark pair production cross-section measurements using ATLAS and CMS data at $\sqrt{s}= 7$ and 8 TeV

The ATLAS & CMS collaborations Aad, G. ; Abbott, B. ; Abbott, D.C. ; et al.
JHEP 07 (2023) 213, 2023.
Inspire Record 2088291 DOI 10.17182/hepdata.110250

A combination of measurements of the inclusive top-quark pair production cross-section performed by ATLAS and CMS in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV at the LHC is presented. The cross-sections are obtained using top-quark pair decays with an opposite-charge electron-muon pair in the final state and with data corresponding to an integrated luminosity of about 5 fb$^{-1}$ at $\sqrt{s}=7$ TeV and about 20 fb$^{-1}$ at $\sqrt{s}=8$ TeV for each experiment. The combined cross-sections are determined to be $178.5 \pm 4.7$ pb at $\sqrt{s}=7$ TeV and $243.3^{+6.0}_{-5.9}$ pb at $\sqrt{s}=8$ TeV with a correlation of 0.41, using a reference top-quark mass value of 172.5 GeV. The ratio of the combined cross-sections is determined to be $R_{8/7}= 1.363\pm 0.032$. The combined measured cross-sections and their ratio agree well with theory calculations using several parton distribution function (PDF) sets. The values of the top-quark pole mass (with the strong coupling fixed at 0.118) and the strong coupling (with the top-quark pole mass fixed at 172.5 GeV) are extracted from the combined results by fitting a next-to-next-to-leading-order plus next-to-next-to-leading-log QCD prediction to the measurements. Using a version of the NNPDF3.1 PDF set containing no top-quark measurements, the results obtained are $m_t^\text{pole} = 173.4^{+1.8}_{-2.0}$ GeV and $\alpha_\text{s}(m_Z)= 0.1170^{+ 0.0021}_{-0.0018}$.

2 data tables

Full covariance matrix including all systematic uncertainties expressed as nuisance parameters. With the exception of the cross section parameters, all parameters were normalised to 1 before the fit. Therefore, the diagonal elements represent the constraint in quadrature.

Full covariance matrix including all systematic uncertainties expressed as nuisance parameters. With the exception of the cross section parameters, all parameters were normalised to 1 before the fit. Therefore, the diagonal elements represent the constraint in quadrature.


Measurements of the associated production of a W boson and a charm quark in proton-proton collisions at $\sqrt{s}$ = 8 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Bergauer, Thomas ; et al.
Eur.Phys.J.C 82 (2022) 1094, 2022.
Inspire Record 1982672 DOI 10.17182/hepdata.114364

Measurements of the associated production of a W boson and a charm (c) quark in proton-proton collisions at a centre-of-mass energy of 8 TeV are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 fb$^{-1}$ collected by the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm quark jets are selected using distinctive signatures of charm hadron decays. The product of the cross section and branching fraction $\sigma$(pp $\to$ W + c + X) $\mathcal{B}$(W $\to$$\ell\nu$), where $\ell$ = e or $\mu$, and the cross section ratio $\sigma$(pp $\to$ W$^+$ + c + X) / $\sigma$(pp $\to$ W$^-$ + $\mathrm{\bar{c}}$ + X) are measured inclusively and differentially as functions of the pseudorapidity and of the transverse momentum of the lepton from the W boson decay. The results are compared with theoretical predictions. The impact of these measurements on the determination of the strange quark distribution is assessed.

6 data tables

Signal yields after background subtraction, efficiency*acceptance correction factors, and cross section measurements for the four channels (W decay to muon or electron and charm identification via muon or secondary vertex inside a jet).

Measured production cross sections $\sigma(W^+ + \overline{c})$, $\sigma(W^- + c)$ and their ratio.

Measured diferential cross sections $\sigma(W^- + c) + \sigma(W^+ + \overline{c})$ as a function of the absolute value of the pseudorapidity of the lepton from the W decay.

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Version 2
Measurement of the top quark mass using events with a single reconstructed top quark in pp collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 12 (2021) 161, 2021.
Inspire Record 1911567 DOI 10.17182/hepdata.102987

A measurement of the top quark mass is performed using a data sample enriched with single top quark events produced in the $t$ channel. The study is based on proton-proton collision data, corresponding to an integrated luminosity of 35.9 fb$^{-1}$, recorded at $\sqrt{s}$ = 13 TeV by the CMS experiment at the LHC in 2016. Candidate events are selected by requiring an isolated high-momentum lepton (muon or electron) and exactly two jets, of which one is identified as originating from a bottom quark. Multivariate discriminants are designed to separate the signal from the background. Optimized thresholds are placed on the discriminant outputs to obtain an event sample with high signal purity. The top quark mass is found to be 172.13 $^{+0.76}_{-0.77}$ GeV, where the uncertainty includes both the statistical and systematic components, reaching sub-GeV precision for the first time in this event topology. The masses of the top quark and antiquark are also determined separately using the lepton charge in the final state, from which the mass ratio and difference are determined to be 0.9952 $^{+0.0079}_{-0.0104}$ and 0.83 $^{+1.79}_{-1.35}$ GeV, respectively. The results are consistent with $CPT$ invariance.

38 data tables

Top quark mass measured inclusive of lepton flavor and charge. The uncertainties are given in two parts, the first part is the combination of statistical (stat) and profiled (prof) uncertainties and the second part is for the experimental (ext) uncetrinaties.

The top quark mass measured inclusive of lepton flavor and charge. The uncertainties are given in two parts, the first is the combination of statistical (stat) and profiled systematic (prof) uncertainties and the second is the externalized systematic (ext) uncertainties.

Top quark mass measured inclusive of lepton flavor and for positively charged lepton.

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Version 4
Measurements of production cross sections of the Higgs boson in the four-lepton final state in proton-proton collisions at $\sqrt{s} = $ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 81 (2021) 488, 2021.
Inspire Record 1850544 DOI 10.17182/hepdata.102525

Production cross sections of the Higgs boson are measured in the H $\to$ ZZ $\to$ $4\ell$ ($\ell$ $=$ e, $\mu$) decay channel. A data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS detector at the LHC and corresponding to an integrated luminosity of 137 fb$^{-1}$ is used. The signal strength modifier $\mu$, defined as the ratio of the Higgs boson production rate in the $4\ell$ channel to the standard model (SM) expectation, is measured to be $\mu$ $=$ 0.94 $\pm$ 0.07 (stat) ${}^{+0.09}_{-0.08}$ (syst) at a fixed value of $m_H$ = 125.38 GeV. The signal strength modifiers for the individual Higgs boson production modes are also reported. The inclusive fiducial cross section for the H $\to$ $4\ell$ process is measured to be 2.84 $^{+0.23}_{-0.22}$ (stat) ${}^{+0.26}_{-0.21}$ (syst) fb, which is compatible with the SM prediction of 2.84 $\pm$ 0.15 fb for the same fiducial region. Differential cross sections as a function of the transverse momentum and rapidity of the Higgs boson, the number of associated jets, and the transverse momentum of the leading associated jet are measured. A new set of cross section measurements in mutually exclusive categories targeted to identify production mechanisms and kinematical features of the events is presented. The results are in agreement with the SM predictions.

52 data tables

Integrated Fiducial Higgs cross section. The first uncertainty is the combined statistical uncertainty, the second is the combined systematic uncertainty. As described in the publication, the fiducial volume for 7 and 8 TeV is different than for 13 TeV.

Integrated Fiducial Higgs cross section. The first uncertainty is the combined statistical uncertainty, the second is the combined systematic uncertainty. As described in the publication, the fiducial volume for 7 and 8 TeV is different than for 13 TeV.

Integrated Fiducial Higgs cross section. The first uncertainty is the combined statistical uncertainty, the second is the combined systematic uncertainty. As described in the publication, the fiducial volume for 7 and 8 TeV is different than for 13 TeV.

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Version 2
Measurements of angular distance and momentum ratio distributions in three-jet and Z + two-jet final states in pp collisions

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 81 (2021) 852, 2021.
Inspire Record 1847230 DOI 10.17182/hepdata.106642

Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and Z + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and Z + two-jet events are based on data collected at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.8 fb$^{-1}$. The Z + two-jet events are reconstructed in the dimuon decay channel of the Z boson. The three-jet measurement is extended to include $\sqrt{s} =$ 13 TeV data corresponding to an integrated luminosity of 2.3 fb$^{-1}$. The results are compared to predictions from event generators that include parton showers, multiple parton interactions, and hadronization. The collinear and soft regions are in general well described by parton showers, whereas the regions of large angular separation are often best described by calculations using higher-order matrix elements.

24 data tables

Three-jet events $p_{\mathrm{T}3}/p_{\mathrm{T}2}$ for small-angle radiation ($\Delta R_{23}$ < 1.0)

Three-jet events $p_{\mathrm{T}3}/p_{\mathrm{T}2}$ for small-angle radiation ($\Delta R_{23}$ < 1.0)

Three-jet events $p_{\mathrm{T}3}/p_{\mathrm{T}2}$ for large-angle radiation ($\Delta R_{23}$ > 1.0)

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Angular analysis of the decay B$^+$ $\to$ K$^*$(892)$^+\mu^+\mu^-$ in proton-proton collisions at $\sqrt{s} =$ 8 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 04 (2021) 124, 2021.
Inspire Record 1826544 DOI 10.17182/hepdata.99387

Angular distributions of the decay B$^+$$\to$ K$^*$(892)$^+\mu^+\mu^-$ are studied using events collected with the CMS detector in $\sqrt{s} =$ 8 TeV proton-proton collisions at the LHC, corresponding to an integrated luminosity of 20.0 fb$^{-1}$. The forward-backward asymmetry of the muons and the longitudinal polarization of the K$^*$(892)$^+$ meson are determined as a function of the square of the dimuon invariant mass. These are the first results from this exclusive decay mode and are in agreement with a standard model prediction.

1 data table

The measured signal yields, FL, AFB in bins of the dimuon invariant mass squared. The first uncertainty is statistical and the second is systematic.


A measurement of the Higgs boson mass in the diphoton decay channel

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 805 (2020) 135425, 2020.
Inspire Record 1780985 DOI 10.17182/hepdata.93362

A measurement of the mass of the Higgs boson in the diphoton decay channel is presented. This analysis is based on 35.9 fb$^{-1}$ of proton-proton collision data collected during the 2016 LHC running period, with the CMS detector at a center-of-mass energy of 13 TeV. A refined detector calibration and new analysis techniques have been used to improve the precision of this measurement. The Higgs boson mass is measured to be $m_\mathrm{H} =$ 125.78 $\pm$ 0.26 GeV. This is combined with a measurement of $m_\mathrm{H}$ already performed in the H $\to$ ZZ $\to$ 4$\ell$ decay channel using the same data set, giving $m_\mathrm{H} =$ 125.46 $\pm$ 0.16 GeV. This result, when further combined with an earlier measurement of $m_\mathrm{H}$ using data collected in 2011 and 2012 with the CMS detector, gives a value for the Higgs boson mass of $m_\mathrm{H} =$ 125.38 $\pm$ 0.14 GeV. This is currently the most precise measurement of the mass of the Higgs boson.

1 data table

A summary of the mass of the Higgs boson measured in the H to GG and the H to ZZ to 4l decay channel, and for the combination of the two. These measurements have been carried out with the Run 1 and 2016 datasets as well as with them combined.


Measurement of the $\chi_\mathrm{c1}$ and $\chi_\mathrm{c2}$ polarizations in proton-proton collisions at $\sqrt{s} =$ 8 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 124 (2020) 162002, 2020.
Inspire Record 1771351 DOI 10.17182/hepdata.92245

The polarizations of promptly produced $\chi_\mathrm{c1}$ and $\chi_\mathrm{c2}$ mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at $\sqrt{s} = $ 8 TeV. The $\chi_\mathrm{c}$ states are reconstructed via their radiative decays $\chi_\mathrm{c}$ $\to$ $\mathrm{J}/\psi\, \gamma$, with the photons being measured through conversions to e$^+$e$^-$, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the $\chi_\mathrm{c2}$ to $\chi_\mathrm{c1}$ yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the $\mathrm{J}/\psi$ $\to$ $\mu^+\mu^-$ decay, in three ranges of $\mathrm{J}/\psi$ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum.

6 data tables

Yield ratios of chi_c2 over chi_c1 mesons as a function of phi (HX) in the J/psi pT range 8-12 GeV

Yield ratios of chi_c2 over chi_c1 mesons as a function of phi (HX) in the J/psi pT range 12-18 GeV

Yield ratios of chi_c2 over chi_c1 mesons as a function of phi (HX) in the J/psi pT range 18-30 GeV

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Measurements of triple-differential cross sections for inclusive isolated-photon+jet events in pp collisions at $\sqrt{s} =$ 8 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 79 (2019) 969, 2019.
Inspire Record 1744422 DOI 10.17182/hepdata.90847

Measurements are presented of the triple-differential cross section for inclusive isolated-photon+jet events in pp collisions at $\sqrt{s} =$ 8 TeV as a function of photon transverse momentum ($p_\mathrm{T}^\gamma$), photon pseudorapidity ($\eta^\gamma$), and jet pseudorapidity ($\eta^\text{jet}$). The data correspond to an integrated luminosity of 19.7 fb$^{-1}$ that probe a broad range of the available phase space, for $|\eta^\gamma|$ $<$ 1.44 and 1.57 $<$ $|\eta^\gamma|$ $<$ 2.50, $|\eta^\text{jet}|$ $<$ 2.5, 40 $<$ $p_\mathrm{T}^\gamma$ $<$ 1000 GeV, and jet transverse momentum, $p_\mathrm{T}^\text{jet}$, $>$ 25 GeV. The measurements are compared to next-to-leading order perturbative quantum chromodynamics calculations, which reproduce the data within uncertainties.

4 data tables

Measured triple-differential cross section distributions as a function of ${p_{T}^{\gamma}}$ in different bins of |${\eta^{\textrm{jet}}}$| for photons in the $|{\eta^{\gamma}}|$ < 0.8 bin.

Measured triple-differential cross section distributions as a function of ${p_{T}^{\gamma}}$ in different bins of |${\eta^{\textrm{jet}}}$| for photons in the 0.8 < $|{\eta^{\gamma}}|$ < 1.44 bin.

Measured triple-differential cross section distributions as a function of ${p_{T}^{\gamma}}$ in different bins of |${\eta^{\textrm{jet}}}$| for photons in the 1.56 < $|{\eta^{\gamma}}|$ < 2.1 bin.

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Studies of B$^*_\mathrm{s2}(5840)^0$ and B$_\mathrm{s1}(5830)^0$ mesons including the observation of the B$^*_\mathrm{s2}(5840)^0\to$ B$^0$K$_\mathrm{S}^0$ decay in proton-proton collisions at $\sqrt{s}=$8 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J.C 78 (2018) 939, 2018.
Inspire Record 1693614 DOI 10.17182/hepdata.85740

Measurements of $\mathrm{B}^*_\mathrm{s2}(5840)^0$ and $\mathrm{B}_\mathrm{s1}(5830)^0$ mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.6 fb$^{-1}$, collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV. The analysis studies $P$-wave $\mathrm{B}^0_\mathrm{S}$ meson decays into $\mathrm{B}^{(*)+}\mathrm{K}^-$ and $\mathrm{B}^{(*)0}\mathrm{K}^0_\mathrm{S}$, where the $\mathrm{B}^+$ and $\mathrm{B}^0$ mesons are identified using the decays $\mathrm{B}^+\to\mathrm{J}/\psi\,\mathrm{K}^+$ and $\mathrm{B}^0\to\mathrm{J}/\psi\,\mathrm{K}^*(892)^0$. The masses of the $P$-wave $\mathrm{B}^0_\mathrm{S}$ meson states are measured and the natural width of the $\mathrm{B}^*_\mathrm{s2}(5840)^0$ state is determined. The first measurement of the mass difference between the charged and neutral $\mathrm{B}^*$ mesons is also presented. The $\mathrm{B}^*_\mathrm{s2}(5840)^0$ decay to $\mathrm{B}^0\mathrm{K}^0_\mathrm{S}$ is observed, together with a measurement of its branching fraction relative to the $\mathrm{B}^*_\mathrm{s2}(5840)^0\to\mathrm{B}^+\mathrm{K}^-$ decay.

12 data tables

The $\mathrm{J}/\psi\mathrm{K}^+$ invariant mass distribution in data

The $\mathrm{J}/\psi\mathrm{K}^{*0}$ invariant mass distribution in data

The $\mathrm{B}^+\pi^-$ invariant mass distribution of the selected candidates in data

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