Abstract
Charged particle production has been studied in neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 0.44 fb−1. Distributions of scaled momenta in the Breit frame are presented for particles in the current fragmentation region. The evolution of these spectra with the photon virtuality, Q 2, is described in the kinematic region 10 < Q 2 < 41000Ge V2. Next-to-leading-order and modified leading-log-approximation QCD calculations as well as predictions from Monte Carlo models are compared to the data. The results are also compared to e + e − annihilation data. The dependences of the pseudorapidity distribution of the particles on Q 2 and on the energy in the γp system, W, are presented and interpreted in the context of the hypothesis of limiting fragmentation.
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References
ZEUS collaboration, M. Derrick et al., Measurement of multiplicity and momentum spectra in the current fragmentation region of the Breit frame at HERA, Z. Phys. C 67 (1995) 93 [hep-ex/9501012] [SPIRES].
ZEUS collaboration, J. Breitweg et al., Observation of scaling violations in scaled momentum distributions at HERA, Phys. Lett. B 414 (1997) 428 [hep-ex/9710011] [SPIRES].
ZEUS collaboration, J. Breitweg et al., Measurement of multiplicity and momentum spectra in the current and target regions of the Breit frame in deep inelastic scattering at HERA, Eur. Phys. J. C 11 (1999) 251 [hep-ex/9903056] [SPIRES].
H1 collaboration, F.D. Aaron et al., Charged particle production in high Q 2 deep-inelastic scattering at HERA, Phys. Lett. B 654 (2007) 148 [arXiv:0706.2456] [SPIRES].
G. Altarelli, R.K. Ellis, G. Martinelli and S.-Y. Pi, Processes involving fragmentation functions beyond the leading order in QCD, Nucl. Phys. B 160 (1979) 301 [SPIRES].
P. Nason and B.R. Webber, Scaling violation in e + e − fragmentation functions: QCD evolution, hadronization and heavy quark mass effects, Nucl. Phys. B 421 (1994) 473 [Erratum ibid. B 480 (1996) 755] [SPIRES].
C.P. Fong and B.R. Webber, Higher order QCD corrections to hadron energy distributions in jets, Phys. Lett. B 229 (1989) 289 [SPIRES].
C.P. Fong and B.R. Webber, One and two particle distributions at small x in QCD jets, Nucl. Phys. B 355 (1991) 54 [SPIRES].
Y.L. Dokshitzer, V.A. Khoze and S.I. Troian, Inclusive particle spectra from QCD cascades, Int. J. Mod. Phys. A 7 (1992) 1875 [SPIRES].
Y.I. Dokshitzer et al., Basics of perturbative QCD, Editions Frontiéres, Gif-sur-Yvette France (1991), pg. 169.
Y.I. Azimov, Y.L. Dokshitzer, V.A. Khoze and S.I. Troyan, Similarity of parton and hadron spectra in QCD jets, Z. Phys. C 27 (1985) 65 [SPIRES].
S. Kretzer, Fragmentation functions from flavour-inclusive and flavour-tagged e + e − annihilations, Phys. Rev. D 62 (2000) 054001 [hep-ph/0003177] [SPIRES].
B.A. Kniehl, G. Kramer and B. Pötter, Strong coupling constant from scaling violations in fragmentation functions, Phys. Rev. Lett. 85 (2000) 5288 [hep-ph/0003297] [SPIRES].
S. Albino, B.A. Kniehl and G. Kramer, Fragmentation functions for light charged hadrons with complete quark flavour separation, Nucl. Phys. B 725 (2005) 181 [hep-ph/0502188] [SPIRES].
S. Albino, B.A. Kniehl and G. Kramer, AKK update: improvements from new theoretical input and experimental data, Nucl. Phys. B 803 (2008) 42 [arXiv:0803.2768] [SPIRES].
D. de Florian, R. Sassot and M. Stratmann, Global analysis of fragmentation functions for pions and kaons and their uncertainties, Phys. Rev. D 75 (2007) 114010 [hep-ph/0703242] [SPIRES].
D. de Florian, R. Sassot and M. Stratmann, Global analysis of fragmentation functions for protons and charged hadrons, Phys. Rev. D 76 (2007) 074033 [arXiv:0707.1506] [SPIRES].
V.A. Khoze and W. Ochs, Perturbative QCD approach to multiparticle production, Int. J. Mod. Phys. A 12 (1997) 2949 [hep-ph/9701421] [SPIRES].
V.A. Khoze, S. Lupia and W. Ochs, Perturbative description of particle spectra at LEP-1.5, Phys. Lett. B 386 (1996) 451 [hep-ph/9604410] [SPIRES].
A. Petersen et al., Multi-hadronic events at E c.m. = 29 GeV and predictions of QCD models from E c.m. = 29 GeV to E c.m. = 93 GeV, Phys. Rev. D 37 (1988) 1 [SPIRES].
TASSO collaboration, W. Braunschweig et al., Global jet properties at 14 GeV to 44 GeV center-of-mass energy in e + e − annihilation, Z. Phys. C 47 (1990) 187 [SPIRES].
AMY collaboration, Y.K. Li et al., Multi-hadron event properties in e + e − annihilation at √s = 52 GeV to 57 GeV, Phys. Rev. D 41 (1990) 2675 [SPIRES].
DELPHI collaboration, P. Abreu et al., Determination of α s from the scaling violation in the fragmentation functions in e + e − annihilation, Phys. Lett. B 311 (1993) 408 [SPIRES].
ZEUS collaboration, S. Chekanov et al., Energy dependence of the charged multiplicity in deep inelastic scattering at HERA, JHEP 06 (2008) 061 [arXiv:0803.3878] [SPIRES].
J. Benecke et al., Hypothesis of limiting fragmentation in high-energy collisions, Phys. Rev. 188 (1969) 2159 [SPIRES].
PHOBOS collaboration, B.B. Back et al., Charged-particle pseudorapidity distributions in Au+Au collisions at s 1/2 NN = 62.4 GeV, Phys. Rev. C 74 (2006) 021901 [nucl-ex/0509034] [SPIRES].
STAR collaboration, J. Adams et al., Multiplicity and pseudorapidity distributions of charged particles and photons at forward pseudorapidity in Au + Au collisions at s 1/2 NN = 62.4 GeV, Phys. Rev. C 73 (2006) 034906 [nucl-ex/0511026] [SPIRES].
PHOBOS collaboration, B.B. Back et al., The significance of the fragmentation region in ultrarelativistic heavy ion collisions, Phys. Rev. Lett. 91 (2003) 052303 [nucl-ex/0210015] [SPIRES].
BRAHMS collaboration, I.G. Bearden et al., Pseudorapidity distributions of charged particles from Au+Au collisions at the maximum RHIC energy, Phys. Rev. Lett. 88 (2002) 202301 [nucl-ex/0112001] [SPIRES].
BRAHMS collaboration, I.G. Bearden et al., Charged particle densities from Au + Au collisions at s 1/2 NN = 130 GeV, Phys. Lett. B 523 (2001) 227 [nucl-ex/0108016] [SPIRES].
ZEUS collaboration, U. Holm ed., The ZEUS detector, status report, unpublished, available on http://www-zeus.desy.de/bluebook/bluebook.html, DESY Germany (1993).
N. Harnew et al., Vertex triggering using time difference measurements in the ZEUS central tracking detector, Nucl. Instrum. Meth. A 279 (1989) 290 [SPIRES].
B. Foster et al., The performance of the ZEUS central tracking detector z-by-timing electronics in a transputer based data acquisition system, Nucl. Phys. (Proc. Suppl.) B 32 (1993) 181 [SPIRES].
ZEUS collaboration, B. Foster et al., The design and construction of the ZEUS central tracking detector, Nucl. Instrum. Meth. A 338 (1994) 254 [SPIRES].
ZEUS collaboration, A. Polini et al., The design and performance of the ZEUS micro vertex detector, Nucl. Instrum. Meth. A 581 (2007) 656 [arXiv:0708.3011] [SPIRES].
M. Derrick et al., Design and construction of the ZEUS barrel calorimeter, Nucl. Instrum. Meth. A 309 (1991) 77 [SPIRES].
ZEUS Calorimeter Group collaboration, A. Andresen et al., Construction and beam test of the ZEUS forward and rear calorimeter, Nucl. Instrum. Meth. A 309 (1991) 101 [SPIRES].
A. Caldwell et al., Design and implementation of a high precision readout system for the ZEUS calorimeter, Nucl. Instrum. Meth. A 321 (1992) 356 [SPIRES].
ZEUS Barrel Calorimeter Group collaboration, A. Bernstein et al., Beam tests of the ZEUS barrel calorimeter, Nucl. Instrum. Meth. A 336 (1993) 23 [SPIRES].
ZEUS collaboration, A. Bamberger et al., The small angle rear tracking detector of ZEUS, Nucl. Instrum. Meth. A 401 (1997) 63 [SPIRES].
ZEUS Presampler Group collaboration, A. Bamberger et al., The presampler for the forward and rear calorimeter in the ZEUS detector, Nucl. Instrum. Meth. A 382 (1996) 419 [hep-ex/9609006] [SPIRES].
ZEUS Luminosity Group collaboration, J. Andruszków et al., First measurement of HERA luminosity by ZEUS lumi monitor, preprint DESY-92-066, DESY, Germany (1992) [SPIRES].
ZEUS collaboration, M. Derrick et al., Measurement of total and partial photon proton cross-sections at 180GeV center-of-mass energy, Z. Phys. C 63 (1994) 391 [SPIRES].
ZEUS Luminosity Group collaboration, J. Andruszkow et al., Luminosity measurement in the ZEUS experiment, Acta Phys. Polon. B 32 (2001) 2025 [SPIRES].
M. Helbich et al., The spectrometer system for measuring ZEUS luminosity at HERA, Nucl. Instrum. Meth. A 565 (2006) 572 [physics/0512153] [SPIRES].
W.H. Smith, K. Tokushuku and L.W. Wiggers, The ZEUS trigger system, in Proceedings of Computing in High Energy Physics (CHEP 92), Annecy France September 21–25 1992, C. Verkerk and W. Wojcik eds., CERN, Geneva Switzerland (1992), pg. 222 [DESY-92-150B] [SPIRES].
P.D. Allfrey et al., The design and performance of the ZEUS global tracking trigger, Nucl. Instrum. Meth. A 580 (2007) 1257 [SPIRES].
H. Abramowicz, A. Caldwell and R. Sinkus, Neural network based electron identification in the ZEUS calorimeter, Nucl. Instrum. Meth. A 365 (1995) 508 [hep-ex/9505004] [SPIRES].
S. Bentvelsen, J. Engelen and P. Kooijman, Reconstruction of (x,Q 2) and extraction of structure functions in neutral current scattering at HERA, in Proceedings of Workshop on Physics at HERA, W. Buchmüller and G. Ingelman eds., volume 1, DESY, Hamburg Germany (1992) [NIKHEF-H-92-02] [SPIRES].
B. Brzozowska, Scaled momentum spectra in deep inelastic scattering at HERA, thesis, to be published, University of Warsaw, Warsaw Poland (2010).
F. Jacquet and A. Blondel, Detection of the charged current event — method II, in Proceedings of the Study for an ep Facility for Europe, U. Amaldi ed., Hamburg Germany (1979), pg. 391 [DESY-79-48] [SPIRES].
S. Albino, B.A. Kniehl, G. Kramer and C. Sandoval, Confronting fragmentation function universality with single hadron inclusive production at HERA and e + e − colliders, Phys. Rev. D 75 (2007) 034018 [hep-ph/0611029] [SPIRES].
A. Bassetto, M. Ciafaloni, G. Marchesini and A.H. Mueller, Jet multiplicity and soft gluon factorization, Nucl. Phys. B 207 (1982) 189 [SPIRES].
A.H. Mueller, Multiplicity and hadron distributions in QCD jets: nonleading terms, Nucl. Phys. B 213 (1983) 85 [SPIRES].
B.R. Webber, A QCD model for jet fragmentation including soft gluon interference, Nucl. Phys. B 238 (1984) 492 [SPIRES].
ZEUS collaboration, S. Chekanov et al., Scaled momentum distributions of charged particles in dijet photoproduction at HERA, JHEP 08 (2009) 077 [arXiv:0904.3466] [SPIRES].
L. Lönnblad, ARIADNE version 4: a program for simulation of QCD cascades implementing the color dipole model, Comput. Phys. Commun. 71 (1992) 15 [SPIRES].
G. Gustafson and U. Pettersson, Dipole formulation of QCD cascades, Nucl. Phys. B 306 (1988) 746 [SPIRES].
G. Ingelman, A. Edin and J. Rathsman, LEPTO 6.5 — a Monte Carlo generator for deep inelastic lepton-nucleon scattering, Comput. Phys. Commun. 101 (1997) 108 [hep-ph/9605286] [SPIRES].
K. Charchula, G.A. Schuler and H. Spiesberger, Combined QED and QCD radiative effects in deep inelastic lepton-proton scattering: the Monte Carlo generator DJANGO6, Comput. Phys. Commun. 81 (1994) 381 [SPIRES].
A. Kwiatkowski, H. Spiesberger and H.J. Möhring, Heracles: an event generator for e p interactions at HERA energies including radiative processes: version 1.0, Comp. Phys. Commun. 69 (1992) 155 [SPIRES].
B. Andersson, G. Gustafson, G. Ingelman and T. Sjöstrand, Parton fragmentation and string dynamics, Phys. Rept. 97 (1983) 31 [SPIRES].
H.-U. Bengtsson and T. Sjöstrand, The Lund Monte Carlo for hadronic processes: PYTHIA version 4.8, Comput. Phys. Commun. 46 (1987) 43 [SPIRES].
T. Sjöstrand, High-energy physics event generation with PYTHIA 5.7 and JETSET 7.4, Comput. Phys. Commun. 82 (1994) 74 [SPIRES].
R. Brun et al., GEANT3, technical report CERN-DD/EE/84-1, CERN, Geneva Switzerland (1987) [SPIRES].
Particle Data Group collaboration, C. Amsler et al., Review of particle physics, Phys. Lett. B 667 (2008) 1 [SPIRES].
P. Dixon, D. Kant and G. Thompson, Fragmentation function scaling violations in the Breit frame, J. Phys. G 25 (1999) 1453 [SPIRES].
P. Deines-Jones et al., Charged particle production in the Pb + Pb system at 158 GeV/c per nucleon, Phys. Rev. C 62 (2000) 014903 [hep-ex/9912008] [SPIRES].
UA5 collaboration, G.J. Alner et al., Scaling of pseudorapidity distributions at c.m. energies up to 0.9 TeV, Z. Phys. C 33 (1986) 1 [SPIRES].
B.B. Back et al., The PHOBOS perspective on discoveries at RHIC, Nucl. Phys. A 757 (2005) 28 [nucl-ex/0410022] [SPIRES].
A. Bialas and M. Jezabek, Bremsstrahlung from colour charges as a source of soft particle production in hadronic collisions, Phys. Lett. B 590 (2004) 233 [hep-ph/0403254] [SPIRES].
T. Tymieniecka and B. Brzozowska, Limiting fragmentation in e + e − annihilation and ep deep inelastic scattering, Acta Phys. Polon. B 40 (2009) 2175 [SPIRES].
Spin Muon (SMC) collaboration, B. Adeva et al., Spin asymmetries for events with high p T hadrons in DIS and an evaluation of the gluon polarization, Phys. Rev. D 70 (2004) 012002 [hep-ex/0402010] [SPIRES].
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ArXiv ePrint: 1001.4026v1
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supported by the Italian National Institute for Nuclear Physics (INFN)
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supported by the Science and Technology Facilities Council, U.K.
supported by an FRGS grant from the Malaysian government
supported by the U.S. National Science Foundation. Any opinion, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
supported by the Polish State Committee for Scientific Research, project No. DESY/256/2006 - 154/DES/2006/03
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supported by RF Presidential grant N 1456.2008.2 for the leading scientific schools and by the Russian Ministry of Education and Science through its grant for Scientific Research on High Energy Physics
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supported in part by the MINERVA Gesellschaft f¨ur Forschung GmbH, the Israel Science Foundation (grant No. 293/02-11.2) and the U.S.-Israel Binational Science Foundation
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This work was supported in part by the Marie Curie Actions Transfer of Knowledge project COCOS (contract MTKD-CT-2004-517186)
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now at DESY group FEB, Hamburg, Germany
also at Moscow State University, Russia
now at University of Liverpool, U.K.
on leave of absence at CERN, Geneva, Switzerland
also at Institute of Theoretical and Experimental Physics, Moscow, Russia
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also at FPACS, AGH-UST, Cracow, Poland
partially supported by Warsaw University, Poland
partially supported by Moscow State University, Russia
also affiliated with DESY, Germany
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This material was based on work supported by the National Science Foundation, while working at the Foundation.
also at Max Planck Institute, Munich, Germany, Alexander von Humboldt Research Award
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An erratum to this article can be found at http://dx.doi.org/10.1007/JHEP10(2010)030
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ZEUS collaboration., Abramowicz, H., Abt, I. et al. Scaled momentum spectra in deep inelastic scattering at HERA. J. High Energ. Phys. 2010, 9 (2010). https://doi.org/10.1007/JHEP06(2010)009
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DOI: https://doi.org/10.1007/JHEP06(2010)009