Production of exclusive dijets in diffractive deep inelastic scattering at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Eur.Phys.J. C76 (2016) 16, 2016.
Inspire Record 1372086 DOI 10.17182/hepdata.73738

Production of exclusive dijets in diffractive deep inelastic $e^\pm p$ scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 372 pb$^{-1}$. The measurement was performed for $\gamma^*-p$ centre-of-mass energies in the range $90 < W < 250$ GeV and for photon virtualities $Q^2 > 25$ GeV$^2$. Energy and transverse-energy flows around the jet axis are presented. The cross section is presented as a function of $\beta$ and $\phi$, where $\beta=x/x_{\rm I\!P}$, $x$ is the Bjorken variable and $x_{\rm I\!P}$ is the proton fractional longitudinal momentum loss. The angle $\phi$ is defined by the $\gamma^*-$dijet plane and the $\gamma^*-e^\pm$ plane in the rest frame of the diffractive final state. The $\phi$ cross section is measured in bins of $\beta$. The results are compared to predictions from models based on different assumptions about the nature of the diffractive exchange.

3 data tables

Differential cross-section $d\sigma/d\beta$ in the kinematic range: $Q^2 > 25 GeV^2$, $90 < W < 250 GeV^2$, $x_{\rm I\!P} < 0.01$, $M_X > 5 GeV$ and $p_{T,jet} > 2 GeV$. The contribution from proton dissociation was subtracted. The uncertainty of the subtraction determines the uncertainty of the normalisation also given in the table.

Differential cross-section $d\sigma/d\phi$ in the kinematic range: $Q^2 > 25 GeV^2$, $90 < W < 250 GeV$, $x_{\rm I\!P} < 0.01$, $M_X > 5 GeV$ and $p_{T,jet} > 2 GeV$. The contribution from proton dissociation was subtracted. The uncertainty of the subtraction determines the uncertainty of the normalisation given in the table.

Results of the fit to the cross-section $d\sigma/d\phi$ in bins of $\beta$. The fitted function is proportional to $(1+A \rm{cos}2\phi)$. The uncertainty includes both statistical and systematical contributions (see text of paper).


Combination of differential D$^{∗\pm}$ cross-section measurements in deep-inelastic ep scattering at HERA

The H1 ZEUS collaborations Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1509 (2015) 149, 2015.
Inspire Record 1353667 DOI 10.17182/hepdata.73328

H1 and ZEUS have published single-differential cross sections for inclusive D$^{∗±}$-meson production in deep-inelastic ep scattering at HERA from their respective final data sets. These cross sections are combined in the common visible phase-space region of photon virtuality Q$^{2}$ > 5 GeV$^{2}$, electron inelasticity 0.02 < y < 0.7 and the D$^{∗±}$ meson’s transverse momentum p$_{T}$(D$^{∗}$) > 1.5 GeV and pseudorapidity |η(D$^{∗}$)| < 1.5. The combination procedure takes into account all correlations, yielding significantly reduced experimental uncertainties. Double-differential cross sections d$^{2}$ σ/dQ$^{2}$dy are combined with earlier D$^{∗±}$ data, extending the kinematic range down to Q$^{2}$ > 1.5 GeV$^{2}$. Perturbative next-to-leading-order QCD predictions are compared to the results.

6 data tables

The combined differential $D^{*\pm}$-production cross section as a function of $p_T(D^{*})$, with its uncorrelated and correlated uncertainties.

The combined differential $D^{*\pm}$-production cross section as a function of $\eta(D^{*})$, with its uncorrelated and correlated uncertainties.

The combined differential $D^{*\pm}$-production cross section as a function of $z(D^{*})$, with its uncorrelated and correlated uncertainties.

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Exclusive electroproduction of J/psi mesons at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Nucl.Phys. B695 (2004) 3-37, 2004.
Inspire Record 647777 DOI 10.17182/hepdata.46277

The exclusive electroproduction of J/psi mesons, ep->epJ/psi, has been studied with the ZEUS detector at HERA for virtualities of the exchanged photon in the ranges 0.15<Q^2<0.8 GeV^2 and 2<Q^2<100 GeV^2 using integrated luminosities of 69 pb^-1 and 83 pb^-1, respectively.The photon-proton centre-of-mass energy was in the range 30<W<220 GeV and the squared four-momentum transfer at the proton vertex |t|<1.The cross sections and decay angular distributions are presented as functions of Q^2, W and t. The effective parameters of the Pomeron trajectory are in agreement with those found in J/psi photoproduction. The spin-density matrix elements, calculated from the decay angular distributions, are consistent with the hypothesis of s-channel helicity conservation. The ratio of the longitudinal to transverse cross sections, sigma_L/sigma_T, grows with Q^2, whilst no dependence on W or t is observed. The results are in agreement with perturbative QCD calculations and exhibit a strong sensitivity to the gluon distribution in the proton.

20 data tables

Cross sections for exclusive J/PSI production as a function of W in the Q**2 region 0.15 to 0.18 GeV**2.

Cross sections for exclusive J/PSI production as a function of W in the Q**2 region 2 to 5 GeV**2.

Cross sections for exclusive J/PSI production as a function of W in the Q**2 region 5 to 10 GeV**2.

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Measurement of isolated photons accompanied by jets in deep inelastic $ep$ scattering

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Lett. B715 (2012) 88-97, 2012.
Inspire Record 1117891 DOI 10.17182/hepdata.60574

The production of isolated high-energy photons accompanied by jets has been measured in deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 326 pb^{-1}. Measurements were made for exchanged photon virtualities, Q^2, in the range 10 to 350 GeV^2. The photons were measured in the transverse-energy and pseudorapidity ranges 4 < ET^gamma < 15 GeV and -0.7 < eta^gamma < 0.9, and the jets were measured in the transverse-energy and pseudorapidity ranges 2.5 < ET^jet <35 GeV and -1.5 < eta^jet < 1.8. Differential cross sections are presented as functions of these quantities. Perturbative QCD predictions give a reasonable description of the shape of the measured cross sections over most of the kinematic range, but the absolute normalisation is typically in disagreement by 20-30%.

6 data tables

The measured differential cross section as a function of Q**2.

The measured differential cross section as a function of X.

The measured differential cross section as a function of the transverse energy of the photon.

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Inclusive dijet cross sections in neutral current deep inelastic scattering at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Eur.Phys.J. C70 (2010) 965-982, 2010.
Inspire Record 875006 DOI 10.17182/hepdata.71338

Single- and double-differential inclusive dijet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 374 pb^-1. The measurement was performed at large values of the photon virtuality, Q^2, between 125 and 20000 GeV^2. The jets were reconstructed with the k_T cluster algorithm in the Breit reference frame and selected by requiring their transverse energies in the Breit frame, E_T,B^jet, to be larger than 8 GeV. In addition, the invariant mass of the dijet system, M_jj, was required to be greater than 20 GeV. The cross sections are described by the predictions of next-to-leading-order QCD.

18 data tables

The measured differential cross-sections $d\sigma/dQ^2$ for inclusive dijet production. The statistical, uncorrelated systematic and jet-energy-scale (ES) uncertainties are shown separately. The multiplicative corrections, ${C_{\rm{QED}}}$, which have been applied to the data and the corrections for hadronisation and ${Z^{0}}$ effects to be applied to the parton-level NLO QCD calculations, ${C_{\rm{hadr}}\cdot C_{\rm{Z^{0}}}}$, are shown in the last two columns.

Inclusive dijet cross-sections ${d\sigma/dx_{\rm{Bj}}}$. Other details as in the caption to Table 1.

Inclusive dijet cross-sections ${d\sigma/d\overline{E^{jet}_{T,B}}}$. Other details as in the caption to Table 1.

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Further studies of the photoproduction of isolated photons with a jet at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1408 (2014) 023, 2014.
Inspire Record 1298390 DOI 10.17182/hepdata.64205

In this extended analysis using the ZEUS detector at HERA, the photoproduction of isolated photons together with a jet is measured for different ranges of the fractional photon energy, $x_\gamma^{\mathrm{meas}}$, contributing to the photon-jet final state. Cross sections are evaluated in the photon transverse-energy and pseudorapidity ranges $6 < E_T^{\gamma} < 15$ GeV and $-0.7 < \eta^{\gamma} < 0.9$, and for jet transverse-energy and pseudorapidity ranges $4 < E_T^{\rm jet} < 35$ GeV and $-1.5 < \eta^{\rm jet} < 1.8$, for an integrated luminosity of 374 $\mathrm{pb}^{-1}$. The kinematic observables studied comprise the transverse energy and pseudorapidity of the photon and the jet, the azimuthal difference between them, the fraction of proton energy taking part in the interaction, and the difference between the pseudorapidities of the photon and the jet. Higher-order theoretical calculations are compared to the results.

7 data tables

Differential cross-section D(SIG)/DET(GAMMA) for photons in the given X(GAMMA) range accompanied by a jet. The corresponding hadronisation corrections are also given.

Differential cross-section D(SIG)/DETARAP(GAMMA) for photons in the given X(GAMMA) range accompanied by a jet. The corresponding hadronisation corrections are also given.

Differential cross-section D(SIG)/DET(JET) for photons in the given X(GAMMA) range accompanied by a jet. The corresponding hadronisation corrections are also given.

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Combination of measurements of inclusive deep inelastic ${e^{\pm }p}$ scattering cross sections and QCD analysis of HERA data

The H1 ZEUS collaborations Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Eur.Phys.J. C75 (2015) 580, 2015.
Inspire Record 1377206 DOI 10.17182/hepdata.68951
9 data tables

HERA combined reduced cross sections $\sigma_{r,\rm NC}^{+}$ for NC $e^{+}p$ scattering at $\sqrt{s} = 318$ GeV; $\delta_{\rm stat}$, $\delta_{\rm uncor}$ and $\delta_{\rm cor}$ represent the statistical, uncorrelated systematic and correlated systematic uncertainties, respectively; $\delta_{\rm rel}$, $\delta_{\gamma p}$, $\delta_{\rm had}$ and $\delta_{1}$ to $\delta_{4}$ are the correlated sources of uncertainties arising from the combination procedure. The uncertainties are quoted in percent relative to $\sigma_{r,\rm NC}^{+}$.

HERA combined reduced cross sections $\sigma_{r,\rm NC}^{+}$ for NC $e^{+}p$ scattering at $\sqrt{s} = 300$ GeV; $\delta_{\rm stat}$, $\delta_{\rm uncor}$ and $\delta_{\rm cor}$ represent the statistical, uncorrelated systematic and correlated systematic uncertainties, respectively; $\delta_{\rm rel}$, $\delta_{\gamma p}$, $\delta_{\rm had}$ and $\delta_{1}$ to $\delta_{4}$ are the correlated sources of uncertainties arising from the combination procedure. The uncertainties are quoted in percent relative to $\sigma_{r,\rm NC}^{+}$.

HERA combined reduced cross sections $\sigma_{r,\rm NC}^{+}$ for NC $e^{+}p$ scattering at $\sqrt{s} = 251$ GeV; $\delta_{\rm stat}$, $\delta_{\rm uncor}$ and $\delta_{\rm cor}$ represent the statistical, uncorrelated systematic and correlated systematic uncertainties, respectively; $\delta_{\rm rel}$, $\delta_{\gamma p}$, $\delta_{\rm had}$ and $\delta_{1}$ to $\delta_{4}$ are the correlated sources of uncertainties arising from the combination procedure. The uncertainties are quoted in percent relative to $\sigma_{r,\rm NC}^{+}$.

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Measurement of inelastic $J/\psi$ and $\psi^\prime$ photoproduction at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1302 (2013) 071, 2013.
Inspire Record 1204785 DOI 10.17182/hepdata.62399

The cross sections for inelastic photoproduction of J/psi and psi^prime mesons have been measured in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 468 pb-1 collected in the period 1996--2007. The psi^prime to J/psi cross section ratio was measured in the range 0.55 < z < 0.9 and 60 < W < 190 GeV as a function of W, z and p_T. Here W denotes the photon-proton centre-of-mass energy, z is the fraction of the incident photon energy carried by the meson and p_T is the transverse momentum of the meson with respect to the beam axis. The J/psi cross sections were measured for 0.1 < z < 0.9, 60 < W < 240 GeV and p_T > 1 GeV. Theoretical predictions within the non-relativistic QCD framework including NLO colour--singlet and colour--octet contributions were compared to the data, as were predictions based on the k_T--factorisation approach.

12 data tables

Cross section ratio PSIPRIME (PSI(2S)) to J/PSI as a function of PT.

Cross section ratio PSIPRIME (PSI(2S)) to J/PSI as a function of W.

Cross section ratio PSIPRIME (PSI(2S)) to J/PSI as a function of Z.

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Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1409 (2014) 127, 2014.
Inspire Record 1298276 DOI 10.17182/hepdata.64204

The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q$^{2}$ < 1000 GeV$^{2}$ using an integrated luminosity of 354 pb$^{−1}$. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q$^{2}$, Bjorken x, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q$^{2}$. The running beauty-quark mass, m$_{b}$ at the scale m$_{b}$ , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m$_{b}$ (m$_{b}$ ) = 4.07 ± 0.14 (fit)$_{− 0.07}^{+ 0.01}$ (mod.)$_{− 0.00}^{+ 0.05}$ (param.)$_{− 0.05}^{+ 0.08}$ (theo.) GeV.

28 data tables

Differential cross sections for inclusive jet production in beauty events as a function of ET(JET) for ET(JET) > 5 GeV. The measurements are given together with their statistical and systematic uncertainties. Hadronisation and QED radiative corrections, CHAD and CRAD, respectively, are also shown.

Differential cross sections for inclusive jet production in charm events as a function of ET(JET) for ET(JET) > 4.2 GeV. The measurements are given together with their statistical and systematic uncertainties. Hadronisation and QED radiative corrections, CHAD and CRAD, respectively, are also shown.

Differential cross sections for inclusive jet production in beauty events as a function of ETARAP(JET) for -1.6 < ETARAP(JET) < 2.2. The measurements are given together with their statistical and systematic uncertainties. Hadronisation and QED radiative corrections, CHAD and CRAD, respectively, are also shown.

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Photoproduction of Isolated Photons, Inclusively and with a Jet, at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Lett. B730 (2014) 293-301, 2014.
Inspire Record 1267651 DOI 10.17182/hepdata.64777

The photoproduction of isolated photons, both inclusive and together with a jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of $374\, \mathrm{pb}^{-1}$. Differential cross sections are presented in the isolated-photon transverse-energy and pseudorapidity ranges $6 < E_T^\gamma < 15$ GeV and $-0.7 < \eta^\gamma < 0.9,$ and for jet transverse-energy and pseudorapidity ranges $4 < E_T^{jet} < 35$ GeV and $-1.5 < \eta^{jet} < 1.8,$ for exchanged-photon virtualities $Q^2 < 1$ GeV$^2$. Differential cross sections are also presented for inclusive isolated-photon production as functions of the transverse energy and pseudorapidity of the photon. Higher-order theoretical calculations are compared to the results.

7 data tables

The measured differential photoproduction cross section DSIG/DET(gamma) for isolated inclusive photons.

The measured differential photoproduction cross section DSIG/DETARAP(gamma) for isolated inclusive photons.

The measured differential photoproduction cross section DSIG/DET(gamma) for isolated photons accompanied by a jet.

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Deep inelastic cross-section measurements at large y with the ZEUS detector at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Rev. D90 (2014) 072002, 2014.
Inspire Record 1292476 DOI 10.17182/hepdata.64778
82 data tables

The reduced cross section for the reaction E+ P --> E+ X at a centre-of-mass energy 318 GeV and Q^2=7 GeV^2 for the central-vertex region. The (sys) error shown in the table is the total systematic uncertainty, excluding the normalisation uncertainties shown separately below.

The reduced cross section for the reaction E+ P --> E+ X at a centre-of-mass energy 318 GeV and Q^2=9 GeV^2 for the central-vertex region. The (sys) error shown in the table is the total systematic uncertainty, excluding the normalisation uncertainties shown separately below.

The reduced cross section for the reaction E+ P --> E+ X at a centre-of-mass energy 318 GeV and Q^2=12 GeV^2 for the central-vertex region. The (sys) error shown in the table is the total systematic uncertainty, excluding the normalisation uncertainties shown separately below.

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Measurement of $D^{\ast}$ photoproduction at three different centre-of-mass energies at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1410 (2014) 3, 2014.
Inspire Record 1297225 DOI 10.17182/hepdata.64174
1 data table

The cross sections for the production of D*+- mesons normalised to the HER data sample.


Measurement of high-Q2 neutral current deep inelastic $e^+p$ scattering cross sections with a longitudinally polarized positron beam at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Rev. D87 (2013) 052014, 2013.
Inspire Record 1183813 DOI 10.17182/hepdata.62614

Measurements of neutral current cross sections for deep inelastic scattering in e+p collisions at HERA with a longitudinally polarized positron beam are presented. The single-differential cross-sections dσ/dQ2, dσ/dx and dσ/dy and the reduced cross section σ˜ are measured in the kinematic region Q2>185  GeV2 and y<0.9, where Q2 is the four-momentum transfer squared, x the Bjorken scaling variable and y the inelasticity of the interaction. The measurements are performed separately for positively and negatively polarized positron beams. The measurements are based on an integrated luminosity of 135.5  pb-1 collected with the ZEUS detector in 2006 and 2007 at a center-of-mass energy of 318 GeV. The structure functions F˜3 and F3γZ are determined by combining the e+p results presented in this paper with previously published e-p neutral current results. The asymmetry parameter A+ is used to demonstrate the parity violation predicted in electroweak interactions. The measurements are well described by the predictions of the Standard Model.

26 data tables

The single-differential cross section DSIG/DQ**2 (Y<0.9,Y(1-x)**2>0.004), corrected to the electroweak Born level, for zero polarisation, Pe=0.

The single-differential cross section DSIG/DQ**2 (Y<0.9,Y(1-x)**2>0.004), corrected to the electroweak Born level, for positive (Pe=+0.32) and negative (Pe=-0.36) polarisations.

The single-differential cross section DSIG/DX (Y<0.9,Y(1-x)**2>0.004) at Q^2=185 GeV^2, corrected to the electroweak Born level, for zero (Pe=0), positive (Pe=+0.32) and negative (Pe=-0.36) polarisations.

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Measurement of neutral current e$\pm$p cross sections at high Bjorken x with the ZEUS detector

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Rev. D89 (2014) 072007, 2014.
Inspire Record 1269458 DOI 10.17182/hepdata.62545

The neutral current e+/-p cross section has been measured up to values of Bjorken x of approximately 1 with the ZEUS detector at HERA using an integrated luminosity of 187 inv. pb of e-p and 142 inv. pb of e+p collisions at sqrt(s) = 318GeV. Differential cross sections in x and Q2, the exchanged boson virtuality, are presented for Q2 geq 725GeV2. An improved reconstruction method and greatly increased amount of data allows a finer binning in the high-x region of the neutral current cross section and leads to a measurement with much improved precision compared to a similar earlier analysis. The measurements are compared to Standard Model expectations based on a variety of recent parton distribution functions.

17 data tables

Double differential cross section for Q^2=725 GeV^2.

Double differential cross section for Q^2=875 GeV^2.

Double differential cross section for Q^2=1025 GeV^2.

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Measurement of $ D^{*\pm}$ production in deep inelastic scattering at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1305 (2013) 097, 2013.
Inspire Record 1225526 DOI 10.17182/hepdata.62363

The production of D (*±) mesons in deep inelastic ep scattering has been measured for exchanged photon virtualities 5 < Q (2) < 1000 GeV(2), using an integrated luminosity of 363 pb(−1) with the ZEUS detector at HERA. Differential cross sections have been measured and compared to next-to-leading-order QCD calculations. The cross-sections are used to extract the charm contribution to the proton structure functions, expressed in terms of the reduced charm cross section, . Theoretical calculations based on fits to inclusive HERA data are compared to the results.

22 data tables

D(SIG)/DPT IN NB/GEV as a function of PT IN GEV.

D(SIG)/DETARAP IN NB as a function of ETARAP.

D(SIG)/DZ IN NB as a function of Z.

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Measurement of $D^\pm$ production in deep inelastic $ep$ scattering with the ZEUS detector at HERA

The ZEUS collaboration Abt, I. ; Adamczyk, L. ; Adamus, M. ; et al.
JHEP 1305 (2013) 023, 2013.
Inspire Record 1220382 DOI 10.17182/hepdata.62364

Charm production in deep inelastic ep scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb^{-1}. Charm quarks were identified by reconstructing D^{+} mesons in the D^{+} -> K^{-} pi^{+} pi^{+} decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5 < Q^{2} < 1000 GeV^{2}, 0.02 < y < 0.7, 1.5 < p_{T}(D^{+}) < 15 GeV and |eta(D^{+})| < 1.6, where Q^{2} is the photon virtuality, y is the inelasticity, and p_{T}(D^{+}) and eta(D^{+}) are the transverse momentum and the pseudorapidity of the D^{+} meson, respectively. Next-to-leading-order QCD predictions are compared to the data. The charm contribution, F_{2}^{cc}, to the proton structure-function F_{2} was extracted.

12 data tables

The bin-averaged differential cross section as a function of Q^2. The (sys) error is the experimental systematic uncertainty, excluding the luminosity and branching ratio uncertainties.

The bin-averaged differential cross section as a function of Y. The (sys) error is the experimental systematic uncertainty, excluding the luminosity and branching ratio uncertainties.

The bin-averaged differential cross section as a function of PT. The (sys) error is the experimental systematic uncertainty, excluding the luminosity and branching ratio uncertainties.

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Measurement of dijet photoproduction for events with a leading neutron at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys. B827 (2010) 1-33, 2010.
Inspire Record 831440 DOI 10.17182/hepdata.62426

Differential cross sections for dijet photoproduction and this process in association with a leading neutron, e+ + p -> e+ + jet + jet + X (+ n), have been measured with the ZEUS detector at HERA using an integrated luminosity of 40 pb-1. The fraction of dijet events with a leading neutron was studied as a function of different jet and event variables. Single- and double-differential cross sections are presented as a function of the longitudinal fraction of the proton momentum carried by the leading neutron, xL, and of its transverse momentum squared, pT**2. The dijet data are compared to inclusive DIS and photoproduction results/ they are all consistent with a simple pion-exchange model. The neutron yield as a function of xL was found to depend only on the fraction of the proton beam energy going into the forward region, independent of the hard process. No firm conclusion can be drawn on the presence of rescattering effects.

13 data tables

The differential cross section as a function of jet transverse energy for dijet photon production both without and with a leading neutron, together with their ratio.

The differential cross section as a function of jet pseudorapidity for dijet photon production both without and with a leading neutron, together with their ratio.

The differential cross section as a function of x_photon, the fraction of the photon 4-momenta entering the hard scattering, for dijet photon production both without and with a leading neutron, together with their ratio.

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Scaled momentum distributions for $K^0_S$ and $\Lambda/\bar{\Lambda}$ in DIS at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1203 (2012) 020, 2012.
Inspire Record 945935 DOI 10.17182/hepdata.62425
6 data tables

The measured scaled momentum distributions for K0S production as a function of Q^2 in three XP regions.

The measured scaled momentum distributions for K0S production as a function of Q^2 in three XP regions.

The measured scaled momentum distributions for K0S production as a function of XP in two Q^2 regions.

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Inclusive-jet photoproduction at HERA and determination of alphas

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Nucl.Phys. B864 (2012) 1-37, 2012.
Inspire Record 1116258 DOI 10.17182/hepdata.62400
12 data tables

The measured differential cross section based on the kT jet algorithm in the kinematic region Q^2<1 GeV^2 and 142 < W < 293 GeV as a function of the jet ET for jet ETARAP -1 TO 2.5 . The first (sys) error is the uncorrelated systematic error and the second is the jet-energy scale uncertainty.

The measured differential cross section based on the kT jet algorithm in the kinematic region Q^2<1 GeV^2 and 142 < W < 293 GeV as a function of the jet ETARAP for jet ET > 17 GeV. The first (sys) error is the uncorrelated systematic error and the second is the jet-energy scale uncertainty.

The measured differential cross section based on the kT jet algorithm in the kinematic region Q^2<1 GeV^2 and 142 < W < 293 GeV as a function of the jet ETARAP for jet ET > 21 GeV. The first (sys) error is the uncorrelated systematic error and the second is the jet-energy scale uncertainty.

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A Measurement of the Q**2, W and t dependences of deeply virtual Compton scattering at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
JHEP 0905 (2009) 108, 2009.
Inspire Record 805219 DOI 10.17182/hepdata.52962

Deeply virtual Compton scattering has been measured in e^+p collisions at HERA with the ZEUS detector using an integrated luminosity of 61.1 pb^-1. Cross sections are presented as a function of the photon virtuality, Q^2, and photon-proton centre-of-mass energy, W, for a wide region of the phase space, Q^2>~1.5 GeV^2 and 40&lt;W&lt;170 GeV. A subsample of events in which the scattered proton is measured in the leading proton spectrometer, corresponding to an integrated luminosity of 31.3 pb^-1, is used for the first direct measurement of the differential cross section as a function of t, where t is the square of the four-momentum transfer at the proton vertex.

5 data tables

The DVCS cross section as a function of Q**2.

The DVCS cross section as a function of W.

The DVCS cross section as a function of W in four Q**2 regions.

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Combined Measurement and QCD Analysis of the Inclusive e+- p Scattering Cross Sections at HERA

The H1 ZEUS collaborations Aaron, F.D. ; Abramowicz, H. ; Abt, I. ; et al.
JHEP 1001 (2010) 109, 2010.
Inspire Record 836107 DOI 10.17182/hepdata.58304

A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised ep scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q^2, and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions HERAPDF1.0 with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.

89 data tables

Combined reduced cross section data and F2 for Neutral Current E+ P scattering at Q**2=0.045 GeV**2.

Combined reduced cross section data and F2 for Neutral Current E+ P scattering at Q**2=0.065 GeV**2.

Combined reduced cross section data and F2 for Neutral Current E+ P scattering at Q**2=0.085 GeV**2.

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Measurement of the energy dependence of the total photon-proton cross section at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Lett. B697 (2011) 184-193, 2011.
Inspire Record 875888 DOI 10.17182/hepdata.57592
2 data tables

Ratios of the cross sections for 3 energy bins. The first DSYS error isthe uncorrelated uncertainty and the second is the correlated uncertainty.

Fitted power law energy dependence.


Measurement of elastic $\phi$ photoproduction at HERA

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Phys.Lett. B377 (1996) 259-272, 1996.
Inspire Record 415642 DOI 10.17182/hepdata.44895

The production of $\phi$ mesons in the reaction $e~{+}p \rightarrow e~{+} \phi p$ ($\phi \rightarrow K~{+}K~{-}$) at a median $Q~{2}$ of $10~{-4} \ \rm{GeV~2}$ has been studied with the ZEUS detector at HERA. The differential $\phi$ photoproduction cross section $d\sigma/dt$ has an exponential shape and has been determined in the kinematic range $0.1<|t|<0.5 \ \rm{GeV~2}$ and $60 < W < 80 \ \rm{GeV}$. An integrated cross section of $\sigma_{\gamma p \rightarrow \phi p} = 0.96 \pm 0.19~{+0.21}_{-0.18}$ $\rm{\mu b}$ has been obtained by extrapolating to {\it t} = 0. When compared to lower energy data, the results show a weak energy dependence of both $\sigma_{\gamma p \rightarrow \phi p}$ and the slope of the $t$ distribution. The $\phi$ decay angular distributions are consistent with $s$-channel helicity conservation. From lower energies to HERA energies, the features of $\phi$ photoproduction are compatible with those of a soft diffractive process.

3 data tables

Numerical values of dsig/dt distribution requested from authors.

Numerical values of dsig/dt distribution read from plot.


Measurement of $D^+$ and $\Lambda_{c}^{+}$ production in deep inelastic scattering at HERA

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
JHEP 1011 (2010) 009, 2010.
Inspire Record 860842 DOI 10.17182/hepdata.57020

Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb^{-1}. The hadronic decay channels D^{+} -> K^{0}_{S} pi^{+}, Lambda_{c}^{+} -> p K^{0}_{S} and Lambda_{c}^{+} -> Lambda pi^{+}, and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < p_{T}(D^{+}, Lambda_{c}^{+}) < 10 GeV, |eta(D^{+}, Lambda_{c}^{+})| < 1.6, 1.5 < Q^{2} < 1000 GeV^{2} and 0.02 < y < 0.7. Inclusive and differential cross sections for the production of D^{+} mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into Lambda_{c}^{+} baryons is extracted.

8 data tables

Total visible cross section for D+ production. The second systematic error is due to the uncertainty in the branching ratios for D+ to (KOS PI+).

Total visible cross section for LAMBDA/C+ production via the decay channel into (P K0S). The second systematic error reflects the uncertainty in the branching ratio to (P K0S).

Total visible cross section for LAMBDA/C+ production via the decay channel into (LAMBDA PI+). The second systematic error reflects the uncertainty in the branching ratio to (LAMBDA PI+).

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Measurement of beauty production in DIS and $F_2^{b\bar{b}}$ extraction at ZEUS

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Eur.Phys.J. C69 (2010) 347-360, 2010.
Inspire Record 855232 DOI 10.17182/hepdata.56879
18 data tables

Total visible cross section for BBAR production and decay into MUON+JET.

Measured differential cross section as a function of Q**2.

Measured differential cross section as a function of the muon transverse momentum.

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