Measurement of the ratio of cross sections for inclusive isolated-photon production in $pp$ collisions at $\sqrt s = 13$ and $8$ TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
JHEP 04 (2019) 093, 2019.
Inspire Record 1717495 DOI 10.17182/hepdata.89370

The ratio of the cross sections for inclusive isolated-photon production in $pp$ collisions at centre-of-mass energies of 13 and 8 TeV is measured using the ATLAS detector at the LHC. The integrated luminosities of the 13 TeV and 8 TeV datasets are 3.2 fb$^{-1}$ and 20.2 fb$^{-1}$, respectively. The ratio is measured as a function of the photon transverse energy in different regions of the photon pseudorapidity. The predictions from next-to-leading-order perturbative QCD calculations are compared with the measured ratio. The experimental systematic uncertainties as well as the uncertainties affecting the predictions are evaluated taking into account the correlations between the two centre-of-mass energies, resulting in a reduction of up to a factor of $2.5$ ($5$) in the experimental (theoretical) systematic uncertainties. The predictions based on several parameterisations of the proton parton distribution functions agree with the data within the reduced experimental and theoretical uncertainties. In addition, this ratio to that of the fiducial cross sections for $Z$ boson production at 13 and 8 TeV using the decay channels $Z \rightarrow e^+e^-$ and $Z \rightarrow \mu^+\mu^-$ is made and compared with the theoretical predictions. In this double ratio, a further reduction of the experimental uncertainty is obtained because the uncertainties arising from the luminosity measurement cancel out. The predictions describe the measurements of the double ratio within the theoretical and experimental uncertainties.

16 data tables match query

Measured ratio of cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $|\eta^{\gamma}|<0.6$.

Predicted ratio of cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $|\eta^{\gamma}|<0.6$.

Measured ratio of cross sections for inclusive isolated-photon production as a function of $E_{\rm T}^{\gamma}$ for $0.6<|\eta^{\gamma}|<1.37$.

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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 match query

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.


Measurement of the cross-section and charge asymmetry of $W$ bosons produced in proton-proton collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Eur.Phys.J.C 79 (2019) 760, 2019.
Inspire Record 1729240 DOI 10.17182/hepdata.89322

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of $20.2~\mbox{fb$^{-1}$}$. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.

8 data tables match query

The correction factors, $C_{W^±,i}$ with their associated systematic uncertainties as a function of $|\eta_{\mu}|$, for $W^+$ and $W^−$

The integrated global correction factor $C_{W^±}$, for $W^+$ and $W^−$

Cross-sections (differential in $\eta_{\mu}$) and asymmetry, as a function of $|\eta_{\mu}|$). The central values are provided along with the statistical and dominant systematic uncertainties: the data statistical uncertainty (Data Stat.), the $E_T^{\textrm{miss}}$ uncertainty, the uncertainties related to muon reconstruction (Muon Reco.), those related to the background, those from MC statistics (MC Stat.), and modelling uncertainties. The uncertainties of the cross-sections are given in percent and those of the asymmetry as an absolute difference from the nominal.

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Measurement of the inclusive cross-section for the production of jets in association with a Z boson in proton-proton collisions at 8 TeV using the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Eur.Phys.J.C 79 (2019) 847, 2019.
Inspire Record 1744201 DOI 10.17182/hepdata.90953

The inclusive cross-section for jet production in association with a Z boson decaying into an electron-positron pair is measured as a function of the transverse momentum and the absolute rapidity of jets using 19.9 fb$^{-1}$ of $\sqrt s = 8$ TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. The measured Z + jets cross-section is unfolded to the particle level. The cross-section is compared with state-of-the-art Standard Model calculations, including the next-to-leading-order and next-to-next-to-leading-order perturbative QCD calculations, corrected for non-perturbative and QED radiation effects. The results of the measurements cover final-state jets with transverse momenta up to 1 TeV, and show good agreement with fixed-order calculations.

20 data tables match query

List of experimentally considered systematic uncertainties for the Z + jets cross-section measurement

The double-differential Z + jets production cross-section as a function of |y_{jet}| in the 25 GeV < p_{T}^{jet} < 50 GeV range. The particle level phase space definition: - 66 GeV < m_{ee} < 116 GeV - |eta_{electron}| < 2.47 - p_{T}^{electron} > 20 GeV - anti-kt R=0.4 jets N>=1 - |y_{jet}| < 3.4 - p_{T}^{jet} > 25 GeV - Delta R(jet, electron) > 0.4

The double-differential Z + jets production cross-section as a function of |y_{jet}| in the 50 GeV < p_{T}^{jet} < 100 GeV range. The particle level phase space definition: - 66 GeV < m_{ee} < 116 GeV - |eta_{electron}| < 2.47 - p_{T}^{electron} > 20 GeV - anti-kt R=0.4 jets N>=1 - |y_{jet}| < 3.4 - p_{T}^{jet} > 25 GeV - Delta R(jet, electron) > 0.4

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Measurement of the $CP$-violating phase $\phi_s$ in $B^0_s \to J/\psi\phi$ decays in ATLAS at 13 TeV

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Eur.Phys.J.C 81 (2021) 342, 2021.
Inspire Record 1776624 DOI 10.17182/hepdata.103066

A measurement of the $B^0_s \to J/\psi\phi$ decay parameters using 80.5 $\mathrm{fb}^{-1}$ of integrated luminosity collected with the ATLAS detector from 13 TeV proton-proton collisions at the LHC is presented. The measured parameters include the $CP$-violating phase $\phi_s$, the width difference $\Delta\Gamma_{s}$ between the $B^0_s$ meson mass eigenstates and the average decay width $\Gamma_{s}$. The values measured for the physical parameters are combined with those from 19.2 $\mathrm{fb}^{-1}$ of 7 TeV and 8 TeV data, leading to the following: \begin{eqnarray*} \phi_s & = & -0.087\phantom{0} \pm 0.036\phantom{0} ~\mathrm{(stat.)} \pm 0.021\phantom{0} ~\mathrm{(syst.)~rad} \\ \Delta\Gamma_{s} & = & \phantom{-}0.0657 \pm 0.0043 ~\mathrm{(stat.)} \pm 0.0037 ~\mathrm{(syst.)~ps}^{-1} \\ \Gamma_{s} & = & \phantom{-}0.6703 \pm 0.0014 ~\mathrm{(stat.)} \pm 0.0018 ~\mathrm{(syst.)~ps}^{-1} \\ \end{eqnarray*} Results for $\phi_s$ and $\Delta\Gamma_{s}$ are also presented as 68% confidence level contours in the $\phi_s$-$\Delta\Gamma_{s}$ plane. Furthermore, the transversity amplitudes and corresponding strong phases are measured. $\phi_s$ and $\Delta\Gamma_{s}$ measurements are in agreement with the Standard Model predictions.

9 data tables match query

Fitted values for the physical parameters of interest with their statistical and systematic uncertainties, for the result of solution (a).

Fitted values for the physical parameters of interest with their statistical and systematic uncertainties, for the result of solution (b).

Fit correlations between the physical parameters of interest, obtained from the fit for solution (a).

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Measurement of differential cross sections for single diffractive dissociation in $\sqrt{s} = 8$ TeV $pp$ collisions using the ATLAS ALFA spectrometer

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
JHEP 02 (2020) 042, 2020.
Inspire Record 1762584 DOI 10.17182/hepdata.93063

A dedicated sample of Large Hadron Collider proton-proton collision data at centre-of-mass energy $\sqrt{s}=8$ TeV is used to study inclusive single diffractive dissociation, $pp \rightarrow Xp$. The intact final-state proton is reconstructed in the ATLAS ALFA forward spectrometer, while charged particles from the dissociated system $X$ are measured in the central detector components. The fiducial range of the measurement is $-4.0 < \log_{10} \xi < -1.6$ and $0.016 < |t| < 0.43 \ {\rm GeV^2}$, where $\xi$ is the proton fractional energy loss and $t$ is the squared four-momentum transfer. The total cross section integrated across the fiducial range is $1.59 \pm 0.13 \ {\rm mb}$. Cross sections are also measured differentially as functions of $\xi$, $t$, and $\Delta \eta$, a variable that characterises the rapidity gap separating the proton and the system $X$. The data are consistent with an exponential $t$ dependence, ${\rm d} \sigma / {\rm d} t \propto \text{e}^{Bt}$ with slope parameter $B = 7.65 \pm 0.34 \ {\rm GeV^{-2}}$. Interpreted in the framework of triple Regge phenomenology, the $\xi$ dependence leads to a pomeron intercept of $\alpha(0) = 1.07 \pm 0.09$.

3 data tables match query

Hadron-level differential SD cross section as a function of Delta Eta.

Hadron-level differential SD cross section as a function of t.

Hadron-level differential SD cross section as a function of log_10 xi.


Version 2
Measurement of the production cross section of three isolated photons in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 781 (2018) 55-76, 2018.
Inspire Record 1644367 DOI 10.17182/hepdata.80511

A measurement of the production of three isolated photons in proton-proton collisions at a centre-of-mass energy $\sqrt{s}$ = 8 TeV is reported. The results are based on an integrated luminosity of 20.2 fb$^{-1}$ collected with the ATLAS detector at the LHC. The differential cross sections are measured as functions of the transverse energy of each photon, the difference in azimuthal angle and in pseudorapidity between pairs of photons, the invariant mass of pairs of photons, and the invariant mass of the triphoton system. A measurement of the inclusive fiducial cross section is also reported. Next-to-leading-order perturbative QCD predictions are compared to the cross-section measurements. The predictions underestimate the measurement of the inclusive fiducial cross section and the differential measurements at low photon transverse energies and invariant masses. They provide adequate descriptions of the measurements at high values of the photon transverse energies, invariant mass of pairs of photons, and invariant mass of the triphoton system.

13 data tables match query

The three isolated photons cross section with systematic and statistical uncertainties as a function of ET(Photon1).

The three isolated photons cross section with systematic and statistical uncertainties as a function of ET(Photon2).

The three isolated photons cross section with systematic and statistical uncertainties as a function of ET(Photon3).

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Measurement of prompt photon production in $\sqrt{s_\mathrm{NN}} = 8.16$ TeV $p$+Pb collisions with ATLAS

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 796 (2019) 230-252, 2019.
Inspire Record 1723858 DOI 10.17182/hepdata.87256

The inclusive production rates of isolated, prompt photons in $p$+Pb collisions at $\sqrt{s_\mathrm{NN}} = 8.16$ TeV are studied with the ATLAS detector at the Large Hadron Collider using a dataset with an integrated luminosity of 165 nb$^{-1}$ recorded in 2016. The cross-section and nuclear modification factor $R_{p\mathrm{Pb}}$ are measured as a function of photon transverse energy from 20 GeV to 550 GeV and in three nucleon-nucleon centre-of-mass pseudorapidity regions, (-2.83,-2.02), (-1.84,0.91), and (1.09,1.90). The cross-section and $R_{p\mathrm{Pb}}$ values are compared with the results of a next-to-leading-order perturbative QCD calculation, with and without nuclear parton distribution function modifications, and with expectations based on a model of the energy loss of partons prior to the hard scattering. The data disfavour a large amount of energy loss and provide new constraints on the parton densities in nuclei.

7 data tables match query

The measured cross sections for prompt, isolated photons with rapidity in (1.09,1.90).

The measured cross sections for prompt, isolated photons with rapidity in (−1.84,0.91).

The measured cross sections for prompt, isolated photons with rapidity in (−2.83,−2.02).

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Search for charged-lepton-flavour violation in $Z$-boson decays with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abbott, Dale Charles ; et al.
Nature Phys. 17 (2021) 819 819-825, 2021.
Inspire Record 1821688 DOI 10.17182/hepdata.96390

The ATLAS experiment at the Large Hadron Collider reports a search for charged-lepton-flavour violation in decays of $Z$ bosons into a τ lepton and an electron or muon of opposite charge.

9 data tables match query

The best-fit expected and observed distributions of the combined NN output in the CRZ$\tau\tau$ for the $\mu\tau$ channel for events with 1-prong $\tau_\text{had-vis}$ candidates. The last bin in each plot includes overflow events.

The best-fit expected and observed distributions of the combined NN output in the CRZ$\tau\tau$ for the $\mu\tau$ channel for events with 3-prong $\tau_\text{had-vis}$ candidates. The last bin in each plot includes overflow events.

The best-fit expected and observed distributions of the combined NN output in the VRSS for the $e\tau$ channel for events with 1-prong $\tau_\text{had-vis}$ candidates. The last bin in each plot includes overflow events.

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Search for lepton-flavor-violation in $Z$-boson decays with $\tau$-leptons with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
Phys.Rev.Lett. 127 (2022) 271801, 2022.
Inspire Record 1865746 DOI 10.17182/hepdata.105516

A search for lepton-flavor-violating $Z\to e\tau$ and $Z\to\mu\tau$ decays with $pp$ collision data recorded by the ATLAS detector at the LHC is presented. This analysis uses 139 fb$^{-1}$ of Run 2 $pp$ collisions at $\sqrt{s}=13$ TeV and is combined with the results of a similar ATLAS search in the final state in which the $\tau$-lepton decays hadronically, using the same data set as well as Run 1 data. The addition of leptonically decaying $\tau$-leptons significantly improves the sensitivity reach for $Z\to\ell\tau$ decays. The $Z\to\ell\tau$ branching fractions are constrained in this analysis to $\mathcal{B}(Z\to e\tau)<7.0\times10^{-6}$ and $\mathcal{B}(Z\to \mu\tau)<7.2\times10^{-6}$ at 95% confidence level. The combination with the previously published analyses sets the strongest constraints to date: $\mathcal{B}(Z\to e\tau)<5.0\times10^{-6}$ and $\mathcal{B}(Z\to \mu\tau)<6.5\times10^{-6}$ at 95% confidence level.

16 data tables match query

The best-fit predicted and observed distributions of the combined NN output in the low-$p_\text{T}$-SR for the $e\tau_\mu$ channel. The first and last bin include underflow and overflow events, respectively.

The best-fit predicted and observed distributions of the combined NN output in the low-$p_\text{T}$-SR for the $\mu\tau_e$ channel. The first and last bin include underflow and overflow events, respectively.

The best-fit predicted and observed distributions of the combined NN output in the high-$p_\text{T}$-SR for the $e\tau_\mu$ channel. The first and last bin include underflow and overflow events, respectively.

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