A study of final-state radiation in decays of Z bosons produced in pp collisions at 7 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M. ; Tumasyan, Armen ; et al.
Phys.Rev.D 91 (2015) 092012, 2015.
Inspire Record 1346843 DOI 10.17182/hepdata.67634

The differential cross sections for the production of photons in Z to mu+ mu- gamma decays are presented as a function of the transverse energy of the photon and its separation from the nearest muon. The data for these measurements were collected with the CMS detector and correspond to an integrated luminosity of 4.7 inverse femtobarns of pp collisions at sqrt(s) = 7 TeV delivered by the CERN LHC. The cross sections are compared to simulations with POWHEG and PYTHIA, where PYTHIA is used to simulate parton showers and final-state photons. These simulations match the data to better than 5%.

8 data tables

Measured differential cross section dsigma/dET in pb/GeV. For the data values, the first uncertainty is statistical and the second is systematic. For the theory values, the uncertainty combines statistical, PDF, and renormalization/factorization scale components.

Measured differential cross section dsigma/dET in pb/GeV given (0.05 < DeltaR < 0.5). For the data values, the first uncertainty is statistical and the second is systematic. For the theory values, the uncertainty combines statistical, PDF, and renormalization/factorization scale components.

Measured differential cross section dsigma/dET in pb/GeV given (0.5 < DeltaR < 3.0). For the data values, the first uncertainty is statistical and the second is systematic. For the theory values, the uncertainty combines statistical, PDF, and renormalization/factorization scale components.

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Angular coefficients of Z bosons produced in pp collisions at $\sqrt{s}$ = 8 TeV and decaying to $\mu^+ \mu^-$ as a function of transverse momentum and rapidity

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Phys.Lett.B 750 (2015) 154-175, 2015.
Inspire Record 1359451 DOI 10.17182/hepdata.69285

Measurements of the five most significant angular coefficients, A[0] through A[4], for Z bosons produced in pp collisions at $\sqrt{s}$ = 8 TeV and decaying to $\mu^+ \mu^-$ are presented as a function of the transverse momentum and rapidity of Z boson. The integrated luminosity of the dataset collected with the CMS detector at the LHC corresponds to 19.7 inverse femtobarns. These measurements provide comprehensive information about Z boson production mechanisms, and are compared to QCD predictions at leading order, next-to-leading order, and next-to-next-to-leading order in perturbation theory.

2 data tables

The five angular coefficients A0 to A4 and A0-A2 in bins of qT for |y| < 1.

The five angular coefficients A0 to A4 and A0-A2 in bins of qT for 1 < |y| < 2.1.


Azimuthal correlations in Z+jets events in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
Eur.Phys.J.C 83 (2023) 722, 2023.
Inspire Record 2172990 DOI 10.17182/hepdata.133278

The production of Z bosons associated with jets is measured in pp collisions at $\sqrt{s}$ = 13 TeV with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3 fb$^{-1}$. The multiplicity of jets with transverse momentum $p_\mathrm{T}$$\gt$ 30 GeV is measured for different regions of the Z boson's $p_\mathrm{T}$(Z), from lower than 10 GeV to higher than 100 GeV. The azimuthal correlation $\Delta \phi$ between the Z boson and the leading jet, as well as the correlations between the two leading jets are measured in three regions of $p_\mathrm{T}$(Z). The measurements are compared with several predictions at leading and next-to-leading orders, interfaced with parton showers. Predictions based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton interactions and higher jet multiplicities are not important. The effects of multiple parton interactions are shown to be important to correctly describe the measured spectra in the low $p_\mathrm{T}$(Z) regions.

15 data tables

The measured cross section as a function of exclusive jet multiplicity, $N_{\text{jets}}$, when $p_T<10$ GeV

The measured cross section as a function of exclusive jet multiplicity, $N_{\text{jets}}$, when $10<p_T<30$ GeV

The measured cross section as a function of exclusive jet multiplicity, $N_{\text{jets}}$, when $30<p_T<50$ GeV

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Charged particle multiplicity distributions in restricted rapidity intervals in Z0 hadronic decays.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Z.Phys.C 52 (1991) 271-281, 1991.
Inspire Record 324035 DOI 10.17182/hepdata.14860

The multiplicity distributions of charged particles in restricted rapidity intervals inZ0 hadronic decays measured by the DELPHI detector are presented. The data reveal a shoulder structure, best visible for intervals of intermediate size, i.e. for rapidity limits around ±1.5. The whole set of distributions including the shoulder structure is reproduced by the Lund Parton Shower model. The structure is found to be due to important contributions from 3-and 4-jet events with a hard gluon jet. A different model, based on the concept of independently produced groups of particles, “clans”, fluctuating both in number per event and particle content per clan, has also been used to analyse the present data. The results show that for each interval of rapidity the average number of clans per event is approximately the same as at lower energies.

15 data tables

Data for both hemispheres.

Data for both hemispheres.

Data for both hemispheres.

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Cross-section measurements for the production of a $Z$ boson in association with high-transverse-momentum jets in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
JHEP 06 (2023) 080, 2023.
Inspire Record 2077570 DOI 10.17182/hepdata.114865

Cross-section measurements for a $Z$ boson produced in association with high-transverse-momentum jets ($p_{\mathrm{T}} \geq 100$ GeV) and decaying into a charged-lepton pair ($e^+e^-,\mu^+\mu^-$) are presented. The measurements are performed using proton-proton collisions at $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of $139$ fb$^{-1}$ collected by the ATLAS experiment at the LHC. Measurements of angular correlations between the $Z$ boson and the closest jet are performed in events with at least one jet with $p_{\mathrm{T}} \geq 500$ GeV. Event topologies of particular interest are the collinear emission of a $Z$ boson in dijet events and a boosted $Z$ boson recoiling against a jet. Fiducial cross sections are compared with state-of-the-art theoretical predictions. The data are found to agree with next-to-next-to-leading-order predictions by NNLOjet and with the next-to-leading-order multi-leg generators MadGraph5_aMC@NLO and Sherpa.

78 data tables

Measured fiducial differential cross sections for the Z boson p$_{\mathrm{T}}$ in Z($\to \ell^{+} \ell^{-}$) + high p$_{\mathrm{T}}$ jets events. The statistical, systematic, and luminosity uncertainties are given.

Measured fiducial differential cross sections for the leading jet p$_{\mathrm{T}}$ in Z($\to \ell^{+} \ell^{-}$) + high p$_{\mathrm{T}}$ jets events. The statistical, systematic, and luminosity uncertainties are given.

Measured fiducial differential cross sections for the jet multiplicity in Z($\to \ell^{+} \ell^{-}$) + high p$_{\mathrm{T}}$ jets events. The statistical, systematic, and luminosity uncertainties are given.

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Determination of $alpha_{s}$ in second order {QCD} from hadronic $Z$ decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Z.Phys.C 54 (1992) 55-74, 1992.
Inspire Record 333272 DOI 10.17182/hepdata.14603

Distributions of event shape variables obtained from 120600 hadronicZ decays measured with the DELPHI detector are compared to the predictions of QCD based event generators. Values of the strong coupling constant αs are derived as a function of the renormalization scale from a quantitative analysis of eight hadronic distributions. The final result, αs(MZ), is based on second order perturbation theory and uses two hadronization corrections, one computed with a parton shower model and the other with a QCD matrix element model.

9 data tables

Experimental differential Thrust distributions.

Experimental differential Oblateness distributions.

Experimental differential C-parameter distributions.

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Determination of alpha-s from hadronic event shapes measured on the Z0 resonance

The L3 collaboration Adrian, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.
Phys.Lett.B 284 (1992) 471-481, 1992.
Inspire Record 334951 DOI 10.17182/hepdata.29157

We present a study of the global event shape variables thrust and heavy jet mass, of energy-energy correlations and of jet multiplicities based on 250 000 hadronic Z 0 decays. The data are compared to new QCD calculations including resummation of leading and next-to-leading logarithms to all orders. We determine the strong coupling constant α s (91.2 GeV) = 0.125±0.003 (exp) ± 0.008 (theor). The first error is the experimental uncertainty. The second error is due to hadronization uncertainties and approximations in the calculations of the higher order corrections.

3 data tables

Measured EEC distribution corrected for detector effects and photon radiation. Errors are combined statistical and systematic uncertainties.

Measured average jet multiplicities for the K_PT algorithm. All numbers are corrected for detector effects and photon radiation. Errors are combined statistical and systematic uncertainties.

Value of strong coupling constant, alpha_s, determined from the data. First error is experimental, the second is theoretical.


Extraction of the width of the W boson from measurements of sigma(p anti-p ---> W + X) x B(W ---> e neutrino) and sigma(p anti-p ---> Z + X) x B(Z ---> e e) and their ratio

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.D 61 (2000) 072001, 2000.
Inspire Record 501703 DOI 10.17182/hepdata.42085

We report on measurements of inclusive cross sections times branching fractions into electrons for W and Z bosons produced in ppbar collisions at sqrts=1.8 TeV.From an integrated luminosity of 84.5 inverse pb recorded in 1994--1995 using the D0 detector at the Fermilab Tevatron, we determine sigma(ppbar->W+X)B(W->e nu) = 2310 +- 10(stat) +- 50(syst) +- 100(lum) pb and sigma(ppbar->Z+X)B(Z->e e) = 221 +- 3(stat) +- 4(syst) +- 10(lum) pb. From these, we derive their Ratio R = 10.43 +- 0.15(stat) +- 0.20(syst) +- 0.10(NLO), B(W->e nu) = 0.1066 +- 0.0015(stat) +- 0.0021(syst) +- 0.0011(theory)+- 0.0011(NLO), and Gamma_W = 2.130 +- 0.030(stat) +- 0.041(syst) +- 0.022(theory) +- 0.021(NLO) GeV. We use the latter to set a 95% confidence level upper limit on the partial decay width of the W boson into non-standard model final states, Gamma_W^{inv}, of 0.168 GeV. Combining these results with those from the 1992--1993 data gives R = 10.54 +- 0.24, Gamma_W = 2.107 +- 0.054 GeV, and a 95% C.L. upper limit on Gamma_W^{inv} of 0.132 GeV. Using a sample with a luminosity of 505 inverse nb taken at sqrts=630 GeV, we measure sigma(ppbar->W+X)B(W->e nu) = 658 +- 67 pb.

2 data tables

Cross sections times branching ratios for W+- and Z0 production. The second DSYS error is due to the uncertainty in the luminosity.

Ratio of W to Z0 cross sections. The second systematic error is due to the uncertainty in the NLO electroweak radiative corrections.


First Measurement of ZZ Production in panti-p Collisions at s**(1/2) = 1.96-TeV

The CDF collaboration Aaltonen, T. ; Adelman, Jahred A. ; Akimoto, T. ; et al.
Phys.Rev.Lett. 100 (2008) 201801, 2008.
Inspire Record 778518 DOI 10.17182/hepdata.42695

We report the first measurement of the cross section for Z boson pair production at a hadron collider. This result is based on a data sample corresponding to 1.9 fb-1 of integrated luminosity from ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. In the llll channel, we observe three ZZ candidates with an expected background of 0.096^{+0.092}_{-0.063} events. In the llnunu channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of llll and llnunu channels, we observe an excess of events with a probability of $5.1\times 10^{-6}$ to be due to the expected background. This corresponds to a significance of 4.4 standard deviations. The measured cross section is sigma(ppbar -> ZZ) = 1.4^{+0.7}_{-0.6} (stat.+syst.) pb, consistent with the standard model expectation.

1 data table

Measured cross section. Errors are combined statistics and systematics.


First measurement of sigma (p anti-p ---> Z) . Br (Z ---> tau tau) at s**(1/2) = 1.96- TeV

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 71 (2005) 072004, 2005.
Inspire Record 666357 DOI 10.17182/hepdata.50921

We present a measurement of the cross section for $Z$ production times the branching fraction to $\tau$ leptons, $\sigma \cdot$Br$(Z\to \tau^+ \tau^-)$, in $p \bar p$ collisions at $\sqrt{s}=$1.96 TeV in the channel in which one $\tau$ decays into $\mu \nu_{\mu} \nu_{\tau}$, and the other into $\rm {hadrons} + \nu_{\tau}$ or $e \nu_e \nu_{\tau}$. The data sample corresponds to an integrated luminosity of 226 pb$^{-1}$ collected with the D{\O}detector at the Fermilab Tevatron collider. The final sample contains 2008 candidate events with an estimated background of 55%. From this we obtain $\sigma \cdot$Br$(Z \to \tau^+ \tau^-)=237 \pm 15$(stat)$\pm 18$(sys)$ \pm 15$(lum) pb, in agreement with the standard model prediction.

1 data table

Measured cross section times branching ratio.