cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17182/hepdata.153487.v1/t32
title: "Table 10.1.3" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 50 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 3$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t33
title: "Table 10.2.1" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $50 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 100 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 1$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t34
title: "Table 10.2.2" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $50 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 100 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 2$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t35
title: "Table 10.2.3" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $50 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 100 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 3$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t36
title: "Table 10.3.1" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $100 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 1$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t37
title: "Table 10.3.2" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $100 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 2$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t38
title: "Table 10.3.3" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: QED correction factors for $100 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$ and $N_{jet} \geq 3$, as estimated with RAPGAP.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t39
title: "Figure 13" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: The correlation matrix for the inclusive measurement. The azimuthal correlation angle $\Delta\phi$ of each lepton--leading-jet pair was assigned a bin ID between 0 to 59 segmented uniformly from 0 to $\pi$. This bin ID was offset by multiples of 60 based on the jet multiplicity so that the pair from a single jet event, as suggested by the MC simulation, was assigned a value between 0 to 59, dijet events were given 60 to 119, trijet 120 to 179, and four or more jets 180 to 239.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t40
title: "Figure 14.1" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: The correlation matrix for $2.5 \;\mathrm{GeV} &lt; p_{T,jet}^{lead} &lt; 7 \;\mathrm{GeV}$. Other details are as in the caption to Fig. 13.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t41
title: "Figure 14.2" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: The correlation matrix for $7 \;\mathrm{GeV} &lt; p_{T,jet}^{lead} &lt; 12 \;\mathrm{GeV}$. Other details are as in the caption to Fig. 13.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.
DOI: 10.17182/hepdata.153487.v1/t42
title: "Figure 14.3" of "The azimuthal correlation between the leading jet and the scattered lepton in deep inelastic scattering at HERA"

description: The correlation matrix for $12 \;\mathrm{GeV} &lt; p_{T,jet}^{lead} &lt; 30 \;\mathrm{GeV}$. Other details are as in the caption to Fig. 13.
description: The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$.A measurement of jet cross sections in the laboratory frame was made in a fiducial region corresponding to photon virtuality $10 \;\mathrm{GeV}^{2} &lt; Q^{2} &lt; 350 \;\mathrm{GeV}^{2}$, inelasticity $0.04 &lt; y &lt; 0.7$, outgoing lepton energy $E_e &gt; 10 \;\mathrm{GeV}$, lepton polar angle $140^\circ &lt; \theta_e &lt; 180^\circ$, jet transverse momentum $2.5 \;\mathrm{GeV} &lt; p_\mathrm{T,jet} &lt; 30 \;\mathrm{GeV}$, and jet pseudorapidity $-1.5 &lt; \eta_\mathrm{jet} &lt; 1.8$.Jets were reconstructed using the $k_\mathrm{T}$ algorithm with the radius parameter $R = 1$.The leading jet in an event is defined as the jet that carries the highest $p_\mathrm{T,jet}$.Differential cross sections, $d\sigma/d\Delta\phi$, were measured as a function of the azimuthal correlation angle in various ranges of leading-jet transverse momentum, photon virtuality and jet multiplicity.Perturbative calculations at $\mathcal{O}(\alpha_{s}^2)$ accuracy successfully describe the data within the fiducial region, although a lower level of agreement is observed near $\Delta\phi \rightarrow \pi$ for events with high jet multiplicity, due to limitations of the perturbative approach in describing soft phenomena in QCD.The data are equally well described by Monte Carlo predictions that supplement leading-order matrix elements with parton showering.