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

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Rev.D 87 (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 polarised positron beam are presented. The single-differential cross-sections d(sigma)/dQ2, d(sigma)/dx and d(sigma)/dy and the reduced cross-section were 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 were performed separately for positively and negatively polarised 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 centre-of-mass energy of 318 GeV. The structure functions F3 and F3(gamma)Z were 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 isolated photons accompanied by jets in deep inelastic ep scattering

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Lett.B 715 (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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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 11 (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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Inclusive-jet cross sections in NC DIS at HERA and a comparison of the kT, anti-kT and SIScone jet algorithms

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Phys.Lett.B 691 (2010) 127-137, 2010.
Inspire Record 848883 DOI 10.17182/hepdata.55309

For the first time, differential inclusive-jet cross sections have been measured in neutral current deep inelastic ep scattering using the anti-kT and SIScone algorithms. The measurements were made for boson virtualities Q^2 > 125 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 82 pb^-1 and the jets were identified in the Breit frame. The performance and suitability of the jet algorithms for their use in hadron-like reactions were investigated by comparing the measurements to those performed with the kT algorithm. Next-to-leading-order QCD calculations give a good description of the measurements. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(alphas^3) terms. Values of alphas(Mz) were extracted from the data; the results are compatible with and have similar precision to the value extracted from the kT analysis.

16 data tables

Measured differential cross section DSIG/DE for inclusive jet production using the anti-KT jet algorithm.

Measured differential cross section DSIG/DE for inclusive jet production using the SIScone jet algorithm.

The measured differential cross section DSIG/DQ**2 for inclusive jet production using the anti-KT jet algorithm.

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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.C 70 (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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Measurement of beauty production in DIS and F_2^bbbar extraction at ZEUS

The ZEUS collaboration Abramowicz, H. ; Abt, I. ; Adamczyk, L. ; et al.
Eur.Phys.J.C 69 (2010) 347-360, 2010.
Inspire Record 855232 DOI 10.17182/hepdata.56879

Beauty production in deep inelastic scattering with events in which a muon and a jet are observed in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb^-1. The fraction of events with beauty quarks in the data was determined using the distribution of the transverse momentum of the muon relative to the jet. The cross section for beauty production was measured in the kinematic range of photon virtuality, Q^2 > 2 Gev^2, and inelasticity, 0.05 < y < 0.7, with the requirement of a muon and a jet. Total and differential cross sections are presented and compared to QCD predictions. The beauty contribution to the structure function F_2 was extracted and is compared to theoretical predictions.

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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Measurement of isolated photon production in deep inelastic ep scattering

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Phys.Lett.B 687 (2010) 16-25, 2010.
Inspire Record 831986 DOI 10.17182/hepdata.54874

Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320pb^-1. Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges 4 &lt; E_T &lt; 15 GeV and -0.7 &lt; eta &lt; 0.9 for exchanged photon virtualities, Q^2, in the range 10 &lt; Q^2 &lt; 350 GeV and for invariant masses of the hadronic system W_X> 5 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q^2, x, E_T and eta. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range.

6 data tables

Measured integrated cross section.

Measured differential cross section DSIG/DET.

Measured differential cross section DSIG/DETARAP.

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Measurement of charged current deep inelastic scattering cross sections with a longitudinally polarised electron beam at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 61 (2009) 223-235, 2009.
Inspire Record 810120 DOI 10.17182/hepdata.51622

Measurements of the cross sections for charged current deep inelastic scattering in e-p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb-1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections dsigma/dQ2, dsigma/dx and dsigma/dy are presented for Q2>200 GeV2. The double-differential cross-section d2sigma/dxdQ2 is presented in the kinematic range 280&lt;Q2&lt;30000 GeV2 and 0.015&lt;x&lt;0.65. The measured cross sections are compared with the predictions of the Standard Model.

38 data tables

Total cross section for CC DIS events for two values of the longitudinal polarization of the electron beam.

Total cross section for CC DIS events as a function of the longitudinal polarization of the electron beam.

Differential cross section DSIG/DQ**2 for the two values of longitudinal polarization of the electron beam.

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Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 63 (2009) 171-188, 2009.
Inspire Record 810112 DOI 10.17182/hepdata.51856

The production of D+- and D0 mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb-1. The measurements cover the kinematic range 5 < Q^2 < 1000 GeV^2, 0.02 < y < 0.7, 1.5 < p_T^D < 15 GeV and eta^D < 1.6. Combinatorial background to the D meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F2^ccbar, to the proton structure function, F2.

21 data tables

Production cross section for (D+ + D-) mesons.

Production cross section for (D0 + DBAR0) mesons not originating from D*+- decays.

Measured D+- cross section as a function of Q**2.

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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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