Measurement of jet production in deep inelastic scattering and NNLO determination of the strong coupling at ZEUS

The ZEUS collaboration Abt, I. ; Aggarwal, R. ; Aushev, V. ; et al.
Eur.Phys.J.C 83 (2023) 1082, 2023.
Inspire Record 2694205 DOI 10.17182/hepdata.145637

A new measurement of inclusive-jet cross sections in the Breit frame in neutral current deep inelastic scattering using the ZEUS detector at the HERA collider is presented. The data were taken in the years 2004 to 2007 at a centre-of-mass energy of $318\,\text{GeV}$ and correspond to an integrated luminosity of $347\,\text{pb}^{-1}$. Massless jets, reconstructed using the $k_t$-algorithm in the Breit reference frame, have been measured as a function of the squared momentum transfer, $Q^2$, and the transverse momentum of the jets in the Breit frame, $p_{\perp,\text{Breit}}$. The measured jet cross sections are compared to previous measurements and to perturbative QCD predictions. The measurement has been used in a next-to-next-to-leading-order QCD analysis to perform a simultaneous determination of parton distribution functions of the proton and the strong coupling, resulting in a value of $\alpha_s(M_Z^2) = 0.1142 \pm 0.0017~\text{(experimental/fit)}$${}^{+0.0006}_{-0.0007}~\text{(model/parameterisation)}$${}^{+0.0006}_{-0.0004}~\text{(scale)}$, whose accuracy is improved compared to similar measurements. In addition, the running of the strong coupling is demonstrated using data obtained at different scales.

6 data tables

<b>Note: in the paper, uncertainties are given in percent. The HEPData table contains absolute numbers. The original data file, containing relative uncertainties as in the paper, is available via the 'Resources' button above.</b> Double-differential inclusive-jet cross sections, $\sigma$. Also listed are the unfolding uncertainty $\delta_\text{unf}$, the sum of the uncorrelated systematic uncertainties $\delta_\text{uncor}$ and the correlated systematic uncertainties associated with the jet-energy scale $\delta_\text{JES}$, the MC model $\delta_\text{model}$, the relative normalisation of the background from unmatched detector-level jets $\delta_\text{fake}$, the relative normalisation of the background from low-$Q^2$ DIS events $\delta_\text{Low-$Q^2$}$, the $(E-p_\text{Z})$-cut boundaries $\delta_{E-p_\text{Z}}$, the track-matching-efficiency correction $\delta_\text{TME}$. Uncertainties for which a single number is listed should be taken as symmetric in the other direction. Not listed explicitly is the luminosity uncertainty of $1.9\%$, which is fully correlated across all points. The last four columns show the QED Born-level correction $c_\text{QED}$ that has been applied to the data as well as the $Z$, $c_Z$, and hadronisation correction $c_\text{Had}$ and associated uncertainty that need to be applied to the theory predictions.

<b>Note: in the paper, uncertainties are given in percent. The HEPData table contains absolute numbers. The original data file, containing relative uncertainties as in the paper, is available via the 'Resources' button above.</b> Breakdown of the uncorrelated uncertainty $\delta_\text{uncor}$ from Table 1. Shown are the uncertainties associated with the reweighting of the MC models ($\delta_\text{rew.}$), the electron-energy scale ($\delta_\text{EES}$), the electron-finding algorithm ($\delta_\text{EM}$), the electron calibration ($\delta_\text{EL}$), the variation of the $p_{T,\text{lab}}$ cut of the jets ($\delta_{p_T}$), the variation of the electron-track momentum-cut boundaries ($\delta_\text{trk.}$), the variation of the $p_T/\sqrt{E_T}$-cut boundaries ($\delta_\text{bal.}$), the variation of the $Z_\text{vertex}$-cut boundaries ($\delta_\text{vtx.}$), the variation of the $R_\text{RCAL}$-cut boundaries ($\delta_\text{rad.}$), the variation of the electron-track distance-cut boundaries ($\delta_\text{DCA}$), the relative normalisation of the background from photoproduction events ($\delta_\text{PHP}$), the polarisation correction ($\delta_\text{pol.}$), the FLT track-veto-efficiency correction ($\delta_\text{FLT}$) and the correction to QED Born-level ($\delta_\text{QED}$). For the asymmetric uncertainties, the upper number corresponds to the upward variation of the corresponding parameter and the lower number corresponds to the downward variation.

Correlation matrix of the unfolding uncertainty within the inclusive-jet cross-section measurement. Correlations are given in percent.

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Version 2
Multi-jet cross sections in charged current e+-p scattering at HERA

The ZEUS collaboration Chekanov, Sergei ; Derrick, M. ; Magill, S. ; et al.
Phys.Rev.D 78 (2008) 032004, 2008.
Inspire Record 780108 DOI 10.17182/hepdata.50599

Jet cross sections were measured in charged current deep inelastic e+-p scattering at high boson virtualities Q^2 with the ZEUS detector at HERA II using an integrated luminosity of 0.36 fb^-1. Differential cross sections are presented for inclusive-jet production as functions of Q^2, Bjorken x and the jet transverse energy and pseudorapidity. The dijet invariant mass cross section is also presented. Observation of three- and four-jet events in charged-current e+-p processes is reported for the first time. The predictions of next-to-leading-order (NLO) QCD calculations are compared to the measurements. The measured inclusive-jet cross sections are well described in shape and normalization by the NLO predictions. The data have the potential to constrain the u and d valence quark distributions in the proton if included as input to global fits.

23 data tables

Differential polarized inclusive jet cross sections as a function of jet pseudorapidity.

Differential polarized inclusive jet cross sections as a function of jet pseudorapidity.

Differential polarized inclusive jet cross sections as a function of jet transverse energy.

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Production of ${\rm K}^{0}_{\rm{S}}$, $\Lambda$ ($\bar{\Lambda}$), $\Xi^{\pm}$ and $\Omega^{\pm}$ in jets and in the underlying event in pp and p$-$Pb collisions

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
JHEP 07 (2023) 136, 2023.
Inspire Record 2182725 DOI 10.17182/hepdata.139083

The production of strange hadrons (K$^{0}_{\rm S}$, $\Lambda$, $\Xi^{\pm}$, and $\Omega^{\pm}$), baryon-to-meson ratios ($\Lambda/{\rm K}^0_{\rm S}$, $\Xi/{\rm K}^0_{\rm S }$, and $\Omega/{\rm K}^0_{\rm S}$), and baryon-to-baryon ratios ($\Xi/\Lambda$, $\Omega/\Lambda$, and $\Omega/\Xi$) associated with jets and the underlying event were measured as a function of transverse momentum ($p_{\rm T}$) in pp collisions at $\sqrt{s} = 13$ TeV and p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with the ALICE detector at the LHC. The inclusive production of the same particle species and the corresponding ratios are also reported. The production of multi-strange hadrons, $\Xi^{\pm}$ and $\Omega^{\pm}$, and their associated particle ratios in jets and in the underlying event are measured for the first time. In both pp and p-Pb collisions, the baryon-to-meson and baryon-to-baryon yield ratios measured in jets differ from the inclusive particle production for low and intermediate hadron $p_{\rm T}$ (0.6$-$6 GeV/$c$). Ratios measured in the underlying event are in turn similar to those measured for inclusive particle production. In pp collisions, the particle production in jets is compared with PYTHIA 8 predictions with three colour-reconnection implementation modes. None of them fully reproduces the data in the measured hadron $p_{\rm T}$ region. The maximum deviation is observed for $\Xi^{\pm}$ and $\Omega^{\pm}$, which reaches a factor of about six. In p-Pb collisions, there is no significant event-multiplicity dependence for particle production in jets, in contrast to what is observed in the underlying event. The presented measurements provide novel constraints on hadronisation and its Monte Carlo description. In particular, they demonstrate that the fragmentation of jets alone is insufficient to describe the strange and multi-strange particle production in hadronic collisions at LHC energies.

44 data tables

$p_{\rm T}$-differential density of inclusive ${\rm K}_{\rm S}^{0}$ and $\Lambda$ ($\overline{\Lambda}$) in pp collisions at $\sqrt{s} = 13$ TeV.

$p_{\rm T}$-differential densities of ${\rm K}_{\rm S}^{0}$ and $\Lambda$ ($\overline{\Lambda}$) in jets and the underlying event in pp collisions at $\sqrt{s} = 13$ TeV.

$p_{\rm T}$-differential density of inclusive $\Xi^{\pm}$ in pp collisions at $\sqrt{s} = 13$ TeV.

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Measurements of jet multiplicity and jet transverse momentum in multijet 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) 742, 2023.
Inspire Record 2170533 DOI 10.17182/hepdata.133279

Multijet events at large transverse momentum ($p_\mathrm{T}$) are measured at $\sqrt{s}$ = 13 TeV using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3 fb$^{-1}$. The multiplicity of jets with $p_\mathrm{T}$$>$ 50 GeV that are produced in association with a high-$p_\mathrm{T}$ dijet system is measured in various ranges of the $p_\mathrm{T}$ of the jet with the highest transverse momentum and as a function of the azimuthal angle difference $\Delta\phi_{1,2}$ between the two highest $p_\mathrm{T}$ jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest $p_\mathrm{T}$ jets. The measurements are compared with leading and next-to-leading order matrix element calculations supplemented with simulations of parton shower, hadronization, and multiparton interactions. In addition, the measurements are compared with next-to-leading order matrix element calculations combined with transverse-momentum dependent parton densities and transverse-momentum dependent parton shower.

17 data tables

Jet multiplicity measured for a leading-pT jet ($p_{T1}$) with 200 < $p_{T1}$ < 400 GeV and for an azimuthal separation between the two leading jets of $0 < \Delta\Phi_{1,2} < 150^{\circ}$. The full breakdown of the uncertainties is displayed, with PU corresponding to Pileup, PREF to Trigger Prefering, PTHAT to the hard-scale (renormalization and factorization scales), MISS and FAKE to the inefficienties and background, LUMI to integrated luminosity. With JES, JER and stat. unc. following the notation in the paper.

Jet multiplicity measured for a leading-pT jet ($p_{T1}$) with 200 < $p_{T1}$ < 400 GeV and for an azimuthal separation between the two leading jets of $150 < \Delta\Phi_{1,2} < 170^{\circ}$. The full breakdown of the uncertainties is displayed, with PU corresponding to Pileup, PREF to Trigger Prefering, PTHAT to the hard-scale (renormalization and factorization scales), MISS and FAKE to the inefficienties and background, LUMI to integrated luminosity. With JES, JER and stat. unc. following the notation in the paper.

Jet multiplicity measured for a leading-pT jet ($p_{T1}$) with 200 < $p_{T1}$ < 400 GeV and for an azimuthal separation between the two leading jets of $170 < \Delta\Phi_{1,2} < 180^{\circ}$. The full breakdown of the uncertainties is displayed, with PU corresponding to Pileup, PREF to Trigger Prefering, PTHAT to the hard-scale (renormalization and factorization scales), MISS and FAKE to the inefficienties and background, LUMI to integrated luminosity. With JES, JER and stat. unc. following the notation in the paper.

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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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Measurement of the production of charm jets tagged with ${\rm D^0}$ mesons in pp collisions at $\sqrt{s}$ = 5.02 and 13 TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
JHEP 06 (2023) 133, 2023.
Inspire Record 2070667 DOI 10.17182/hepdata.134031

The measurement of the production of charm jets, identified by the presence of a ${\rm D^0}$ meson in the jet constituents, is presented in proton-proton collisions at centre-of-mass energies of $\sqrt{s}$ = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The ${\rm D^0}$ mesons were reconstructed from their hadronic decay ${\rm D^0} \rightarrow {\rm K^-}\pi^+$ and the respective charge conjugate. Jets were reconstructed from ${\rm D^0}$-meson candidates and charged particles using the anti-$k_{\rm T}$ algorithm, in the jet transverse momentum range $5<p_{\rm T;chjet}<50$ GeV/$c$, pseudorapidity $|\eta_{\rm jet}| <0.9-R$, and with the jet resolution parameters $R$ = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a ${\rm D^0}$ meson along the jet axis ($z^{\rm ch}_{||}$) was measured in the range $0.4 < z^{\rm ch}_{||} < 1.0$ in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low $p_{\rm T;chjet}$. Measurements were also done for $R = 0.3$ at $\sqrt{s}$ = 5.02 TeV and are shown along with their comparisons to theoretical predictions in an appendix to this paper.

11 data tables

$p_{\mathrm{T,ch\ jet}}$-differential cross section of charm jets tagged with $\mathrm{D^{0}}$ mesons for $R=0.2$, $0.4$, and $0.6$ in pp collisions at $\sqrt{s}=13$ TeV.

$p_{\mathrm{T,ch\ jet}}$-differential cross section of charm jets tagged with $\mathrm{D^{0}}$ mesons for $R=0.2$, $0.4$, and $0.6$ in pp collisions at $\sqrt{s}=5.02$ TeV.

Ratio of $p_{\mathrm{T,ch\ jet}}$-differential cross section of charm jets tagged with $\mathrm{D^{0}}$ mesons in pp collisions at $\sqrt{s}=13$ TeV to $\sqrt{s}=5.02$ TeV for $R=0.2$, $0.4$, and $0.6$.

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Measurement of differential $b\bar{b}$- and $c\bar{c}$-dijet cross-sections in the forward region of $pp$ collisions at $\sqrt{s}=13 ~ \mathrm{TeV}$

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Ackernley, Thomas ; et al.
JHEP 02 (2021) 023, 2021.
Inspire Record 1823739 DOI 10.17182/hepdata.110430

The inclusive $b \bar{b}$- and $c \bar{c}$-dijet production cross-sections in the forward region of $pp$ collisions are measured using a data sample collected with the LHCb detector at a centre-of-mass energy of 13 TeV in 2016. The data sample corresponds to an integrated luminosity of 1.6 fb$^{-1}$. Differential cross-sections are measured as a function of the transverse momentum and of the pseudorapidity of the leading jet, of the rapidity difference between the jets, and of the dijet invariant mass. A fiducial region for the measurement is defined by requiring that the two jets originating from the two $b$ or $c$ quarks are emitted with transverse momentum greater than 20 GeV$/c$, pseudorapidity in the range $2.2 < \eta < 4.2$, and with a difference in the azimuthal angle between the two jets greater than 1.5. The integrated $b \bar{b}$-dijet cross-section is measured to be $53.0 \pm 9.7$ nb, and the total $c \bar{c}$-dijet cross-section is measured to be $73 \pm 16$ nb. The ratio between $c \bar{c}$- and $b \bar{b}$-dijet cross-sections is also measured and found to be $1.37 \pm 0.27$. The results are in agreement with theoretical predictions at next-to-leading order.

17 data tables

The total $b \bar{b}$-dijet and $c \bar{c}$-dijet cross-sections and their ratio in the fiducial region, compared with the NLO predictions. The first uncertainty is the combined statistical and systematic uncertainty and the second is the uncertainty from the luminosity. For the predictions, the first uncertainty corresponds to the scale uncertainty, the second to the PDF uncertainty.

Numerical results of $b \bar{b}$- and $c \bar{c}$-dijet cross-sections, $c \bar{c}$/$b \bar{b}$ dijet cross-section ratios and their total uncertainties as a function of the leading jet $\eta$ (pseudorapidity).

Numerical results of $b \bar{b}$- and $c \bar{c}$-dijet cross-sections, $c \bar{c}$/$b \bar{b}$ dijet cross-section ratios and their total uncertainties as a function of $\Delta y^*$.

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Measurement of differential cross sections for the production of a Z boson in association with jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
Phys.Rev.D 108 (2023) 052004, 2023.
Inspire Record 2078067 DOI 10.17182/hepdata.115655

A measurement is presented of the production of Z bosons that decay into two electrons or muons in association with jets, in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data were recorded by the CMS Collaboration at the LHC with an integrated luminosity of 35.9 fb$^{-1}$. The differential cross sections are measured as a function of the transverse momentum ($p_\mathrm{T}$) of the Z boson and the transverse momentum and rapidities of the five jets with largest $p_\mathrm{T}$. The jet multiplicity distribution is measured for up to eight jets. The hadronic activity in the events is estimated using the scalar sum of the $p_\mathrm{T}$ of all the jets. All measurements are unfolded to the stable particle-level and compared with predictions from various Monte Carlo event generators, as well as with expectations at leading and next-to-leading orders in perturbative quantum chromodynamics.

70 data tables

Measured cross section as a function of exclusive jet multiplicity, $N_{\text{jets}}$, and breakdown of the relative uncertainty.

Bin-to-bin correlation in the measured cross section as a function of exclusive jet multiplicity, $N_{\text{jets}}$.

Measured cross section as a function of the rapidity absolute value of the first jet, $|y(\text{j}_1)|$, and breakdown of the relative uncertainty.

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Production of $\Lambda$ and ${\rm K}^{0}_{\rm S}$ in jets in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5$ TeV and pp collisions at $\sqrt{s} = 7$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 827 (2022) 136984, 2022.
Inspire Record 2048607 DOI 10.17182/hepdata.129068

The production of $\Lambda$ baryons and ${\rm K}^{0}_{\rm S}$ mesons (${\rm V}^{0}$ particles) was measured in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV and pp collisions at $\sqrt{s} = 7$ TeV with ALICE at the LHC. The production of these strange particles is studied separately for particles associated with hard scatterings and the underlying event to shed light on the baryon-to-meson ratio enhancement observed at intermediate transverse momentum ($p_{\rm T}$) in high multiplicity pp and p-Pb collisions. Hard scatterings are selected on an event-by-event basis with jets reconstructed with the anti-$k_{\rm T}$ algorithm using charged particles. The production of strange particles associated with jets $p_{\rm T,\;jet}^{\rm ch}>10$ and $p_{\rm T,\;jet}^{\rm ch}>20$ GeV/$c$ in p-Pb collisions, and with jet $p_{\rm T,\;jet}^{\rm ch}>10$ GeV/$c$ in pp collisions is reported as a function of $p_{\rm T}$. Its dependence on angular distance from the jet axis, $R({\rm V}^{0},\;{\rm jet})$, for jets with $p_{\rm T,\;jet}^{\rm ch}>10$ GeV/$c$ in p-Pb collisions is reported as well. The $p_{\rm T}$-differential production spectra of strange particles associated with jets are found to be harder compared to that in the underlying event and both differ from the inclusive measurements. In events containing a jet, the density of the ${\rm V}^{0}$ particles in the underlying event is found to be larger than the density in the minimum bias events. The $\Lambda/{\rm K}^{0}_{\rm S}$ ratio associated with jets in p-Pb collisions is consistent with the ratio in pp collisions and follows the expectation of jets fragmenting in vacuum. On the other hand, this ratio within jets is consistently lower than the one obtained in the underlying event and it does not show the characteristic enhancement of baryons at intermediate $p_{\rm T}$ often referred to as "baryon anomaly" in the inclusive measurements.

11 data tables

$p_{\rm T}$-differential density of inclusive ${\rm V}^{0}$ particles in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV.

$p_{\rm T}$-differential density of ${\rm V}^{0}$ particles in underlying events (perp. cone) in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV.

$p_{\rm T}$-differential densities of ${\rm V}^{0}$ particles selected with $R({\rm V}^{0},{\rm jet}) < 0.4$ and that produced in jets in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV.

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Version 2
Production of D*+- mesons with dijets in deep-inelastic scattering at HERA.

The H1 collaboration Aktas, A. ; Andreev, V. ; Anthonis, T. ; et al.
Eur.Phys.J.C 51 (2007) 271-287, 2007.
Inspire Record 736052 DOI 10.17182/hepdata.45686

Inclusive D* production is measured in deep-inelastic ep scattering at HERA with the H1 detector. In addition, the production of dijets in events with a D* meson is investigated. The analysis covers values of photon virtuality 2< Q^2 <=100 GeV^2 and of inelasticity 0.05<= y <= 0.7. Differential cross sections are measured as a function of Q^2 and x and of various D* meson and jet observables. Within the experimental and theoretical uncertainties all measured cross sections are found to be adequately described by next-to-leading order (NLO) QCD calculations, based on the photon-gluon fusion process and DGLAP evolution, without the need for an additional resolved component of the photon beyond what is included at NLO. A reasonable description of the data is also achieved by a prediction based on the CCFM evolution of partons involving the k_T-unintegrated gluon distribution of the proton.

62 data tables

Visible cross section for inclusive D*+- production.

Visible cross section for inclusive D*+- production.

Visible cross section for inclusive D*+- production with two jets.

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