Abstract
A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e ± p 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.
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References
H. Collaboration, Measurement of the inclusive ep scattering cross section at low Q 2 and x at HERA, Eur. Phys. J. C 63 (2009) 625 [arXiv:0904.0929] [SPIRES].
H1 collaboration, F.D. Aaron et al., A precision measurement of the inclusive ep scattering cross section at HERA, Eur. Phys. J. C 64 (2009) 561 [arXiv:0904.3513] [SPIRES].
H1 collaboration, C. Adloff et al., Measurement of neutral and charged current cross-sections in positron proton collisions at large momentum transfer, Eur. Phys. J. C 13 (2000) 609 [hep-ex/9908059] [SPIRES].
H1 collaboration, C. Adloff et al., Measurement of neutral and charged current cross-sections in electron-proton collisions at high Q 2, Eur. Phys. J. C 19 (2001) 269 [hep-ex/0012052] [SPIRES].
H1 collaboration, C. Adloff et al., Measurement and QCD analysis of neutral and charged current cross sections at HERA, Eur. Phys. J. C 30 (2003) 1 [hep-ex/0304003] [SPIRES].
ZEUS collaboration, J. Breitweg et al., Measurement of the proton structure function F 2 and σ tot (γ*p) at low Q 2 and very low x at HERA, Phys. Lett. B 407 (1997) 432 [hep-ex/9707025] [SPIRES].
ZEUS collaboration, J. Breitweg et al., Measurement of the proton structure function F 2 at very low Q 2 at HERA, Phys. Lett. B 487 (2000) 53 [hep-ex/0005018] [SPIRES].
ZEUS collaboration, J. Breitweg et al., ZEUS results on the measurement and phenomenology of F 2 at low x and low Q 2, Eur. Phys. J. C 7 (1999) 609 [hep-ex/9809005] [SPIRES].
ZEUS collaboration, S. Chekanov et al., Measurement of the neutral current cross section and F 2 structure function for deep inelastic e+ p scattering at HERA, Eur. Phys. J. C 21 (2001) 443 [hep-ex/0105090] [SPIRES].
ZEUS collaboration, J. Breitweg et al., Measurement of high-Q 2 charged-current e + p deep inelastic scattering cross sections at HERA, Eur. Phys. J. C 12 (2000) 411 [Erratum ibid. C 27 (2003) 305] [hep-ex/9907010] [SPIRES].
ZEUS collaboration, S. Chekanov et al., Measurement of high-Q 2 e − p neutral current cross sections at HERA and the extraction of xF3, Eur. Phys. J. C 28 (2003) 175 [hep-ex/0208040] [SPIRES].
ZEUS collaboration, S. Chekanov et al., Measurement of high-Q 2 charged current cross sections in e − p deep inelastic scattering at HERA, Phys. Lett. B 539 (2002) 197 [Erratum ibid. B 552 (2003) 308] [hep-ex/0205091] [SPIRES].
ZEUS collaboration, S. Chekanov et al., High-Q 2 neutral current cross sections in e + p deep inelastic scattering at √s = 318GeV, Phys. Rev. D 70 (2004) 052001 [hep-ex/0401003] [SPIRES].
ZEUS collaboration, S. Chekanov et al., Measurement of high-Q 2 charged current cross sections in e+ p deep inelastic scattering at HERA, Eur. Phys. J. C 32 (2003) 1 [hep-ex/0307043] [SPIRES].
A. Glazov, Averaging of DIS cross section data, AIP Conf. Proc. 792 (2005) 237 [SPIRES].
M. Klein and R. Yoshida, Collider physics at HERA, Prog. Part. Nucl. Phys. 61 (2008) 343 [arXiv:0805.3334] [SPIRES].
ZEUS collaboration, S. Chekanov et al., An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment, Eur. Phys. J. C 42 (2005) 1 [hep-ph/0503274] [SPIRES].
M. Klein and T. Riemann, Electroweak interactions probing the nucleon structure, Z. Phys. C 24 (1984) 151 [SPIRES].
Particle Data Group collaboration, C. Amsler et al., Review of particle physics, Phys. Lett. B 667 (2008) 1 [SPIRES].
C.G. Callan, Jr. and D.J. Gross, High-energy electroproduction and the constitution of the electric current, Phys. Rev. Lett. 22 (1969) 156 [SPIRES].
V.N. Gribov and L.N. Lipatov, Deep inelastic ep scattering in perturbation theory, Sov. J. Nucl. Phys. 15 (1972) 438 [SPIRES].
V.N. Gribov and L.N. Lipatov, e + e − pair annihilation and deep inelastic ep scattering in perturbation theory, Sov. J. Nucl. Phys. 15 (1972) 675 [Yad. Fiz. 15 (1972) 1218] [SPIRES].
L.N. Lipatov, The parton model and perturbation theory, Sov. J. Nucl. Phys. 20 (1975) 94 [Yad. Fiz. 20 (1974) 181] [SPIRES].
Y.L. Dokshitzer, Calculation of the structure functions for deep inelastic scattering and e + e − annihilation by perturbation theory in quantum chromodynamics, Sov. Phys. JETP 46 (1977) 641 [Zh. Eksp. Teor. Fiz. 73 (1977) 1216] [SPIRES].
G. Altarelli and G. Parisi, Asymptotic freedom in parton language, Nucl. Phys. B 126 (1977) 298 [SPIRES].
F. Jacquet and A. Blondel, Detection and study of the charged current event, in ep facility for Europe, U. Amaldi ed., Hamburg, Germany (1979).
U. Bassler and G. Bernardi, On the kinematic reconstruction of deep inelastic scattering at HERA: the Sigma method, Nucl. Instrum. Meth. A 361 (1995) 197 [hep-ex/9412004] [SPIRES].
S. Bentvelsen et al., Reconstruction of (x,Q2) and extraction of structure functions in neutral scattering at HERA, in the proceedings of the Workshop on HERA Physics, W. Buchmuller and G. Ingelman eds., DESY, Hamburg, Germany (1992), volume 1, page 23.
K. Hoeger, Measurement of x, y, Q 2 in neutral current events, in the proceedings of the Workshop on HERA Physics, W. Buchmuller and G. Ingelman eds., DESY, Hamburg, Germany (1992), volume 1, page 43.
ZEUS collaboration, M. Derrick et al., Measurement of the F 2 structure function in deep inelastic e + p scattering using 1994 data from the ZEUS detector at HERA, Z. Phys. C 72 (1996) 399 [hep-ex/9607002] [SPIRES].
H1 collaboration, I. Abt et al., The H1 detector at HERA, Nucl. Instrum. Meth. A 386 (1997) 310.
H1 collaboration, I. Abt et al., The tracking, calorimeter and muon detectors of the H1 experiment at HERA, Nucl. Instrum. Meth. A 386 (1997) 348.
H1 collaboration, R.D. Apphhn et al., The H1 lead/scintillating-fibre calorimeter, Nucl. Instrum. Meth. A 386 (1997) 397.
ZEUS collaboration, U. Holm, The ZEUS detector. Status Report, unpublished, DESY (1993), http://www-zeus.desy.de/bluebook/bluebook.html.
H1 collaboration, C. Adloff et al., A measurement of the proton structure function F 2(x,Q 2) at low x and low Q 2 at HERA, Nucl. Phys. B 497 (1997) 3 [hep-ex/9703012] [SPIRES].
H1 collaboration, C. Adloff et al., Deep-inelastic inclusive ep scattering at low x and a determination of α s , Eur. Phys. J. C 21 (2001) 33 [hep-ex/0012053] [SPIRES].
The combined data together with the full correlation information is provided at https://www.desy.de/h1zeus/.
BCDMS collaboration, A.C. Benvenuti et al., A high statistics measurement of the proton structure functions F 2(x,Q 2) and R from deep inelastic muon scattering at high Q 2, Phys. Lett. B 223 (1989) 485 [SPIRES].
New Muon collaboration, M. Arneodo et al., Measurement of the proton and deuteron structure functions, F 2(p) and F 2(d) and of the ratio σ L /σ T , Nucl. Phys. B 483 (1997) 3 [hep-ph/9610231] [SPIRES].
J. Pumplin et al., New generation of parton distributions with uncertainties from global QCD analysis, JHEP 07 (2002) 012 [hep-ph/0201195] [SPIRES].
S. Alekhin, Parton distributions from deep-inelastic scattering data, Phys. Rev. D 68 (2003) 014002 [hep-ph/0211096] [SPIRES].
M. Botje, A QCD analysis of HERA and fixed target structure function data, Eur. Phys. J. C 14 (2000) 285 [hep-ph/9912439] [SPIRES].
ZEUS collaboration, S. Chekanov et al., A ZEUS Next-to-Leading-Order QCD analysis of data on deep inelastic scattering, Phys. Rev. D 67 (2003) 012007 [hep-ex/0208023] [SPIRES].
A.D. Martin, R.G. Roberts, W.J. Stirling and R.S. Thorne, MRST 2001: partons and α s from precise deep inelastic scattering and Tevatron jet data, Eur. Phys. J. C 23 (2002) 73 [hep-ph/0110215] [SPIRES].
A.D. Martin, W.J. Stirling, R.S. Thorne and G. Watt, Parton distributions for the LHC, Eur. Phys. J. C 63 (2009) 189 [arXiv:0901.0002] [SPIRES].
A. Cooper-Sarkar and C. Gwenlan, Comparison and combination of ZEUS and H1 PDF analyses, hep-ph/0508304 [SPIRES].
S.I. Alekhin, Comparative study of the uncertainties in parton distribution functions, Nucl. Instrum. Meth. A 502 (2003) 761.
M. Botje, QCDNUM version 17β, http://www.nikhef.nl/h24/qcdnum/index.html.
C. Pascaud and F. Zomer, QCD analysis from the proton structure function F 2 measurement: issues on fitting, statistical and systematic errors, preprint LAL-95-05 [SPIRES].
R.S. Thorne and R.G. Roberts, An ordered analysis of heavy flavour production in deep inelastic scattering, Phys. Rev. D 57 (1998) 6871 [hep-ph/9709442] [SPIRES].
R.S. Thorne, A variable-flavour number scheme for NNLO, Phys. Rev. D 73 (2006) 054019 [hep-ph/0601245] [SPIRES].
R.S. Thorne, private communication (2008).
P.M. Nadolsky et al., Implications of CTEQ global analysis for collider observables, Phys. Rev. D 78 (2008) 013004 [arXiv:0802.0007] [SPIRES].
M. Krämer, 1, F.I. Olness and D.E. Soper, Treatment of heavy quarks in deeply inelastic scattering, Phys. Rev. D 62 (2000) 096007 [hep-ph/0003035] [SPIRES].