Abstract
Isolated photons with high transverse energy have been studied in deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 326 pb−1 in the range of exchanged-photon virtuality 10-350 GeV2. Outgoing isolated photons with transverse energy 4 < E γ T < 15 GeV and pseudorapidity − 0.7 < ηγ < 0.9 were measured with accompanying jets having transverse energy and pseudorapidity 2.5 < E jet T < 35 GeV and −1.5 < ηjet < 1.8, respectively. Differential cross sections are presented for the following variables: the fraction of the incoming photon energy and momentum that is transferred to the outgoing photon and the leading jet; the fraction of the incoming proton energy transferred to the photon and leading jet; the differences in azimuthal angle and pseudorapidity between the outgoing photon and the leading jet and between the outgoing photon and the scattered electron. Comparisons are made with theoretical predictions: a leading-logarithm Monte Carlo simulation, a next-to-leading-order QCD prediction, and a prediction using the k T -factorisation approach.
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References
E. Anassontzis et al., High p T direct photon production in pp collisions, Z. Phys. C 13 (1982) 277 [INSPIRE].
WA70 collaboration, M. Bonesini et al., Production of high transverse momentum prompt photons and neutral pions in proton proton interactions at 280 GeV/c, Z. Phys. C 38 (1988) 371 [INSPIRE].
FERMILAB-E706 collaboration, G. Alverson et al., Production of direct photons and neutral mesons at large transverse momenta by π − and p beams at 500 GeV/c, Phys. Rev. D 48 (1993) 5 [INSPIRE].
CDF collaboration, F. Abe et al., A Precision measurement of the prompt photon cross-section in \( p\overline{p} \) collisions at \( \sqrt{s}=1.8 \) TeV, Phys. Rev. Lett. 73 (1994) 2662 [Erratum ibid. 74 (1995) 1891] [INSPIRE].
CDF collaboration, D. Acosta et al., Measurement of the cross section for prompt diphoton production in \( p\overline{p} \) collisions at \( \sqrt{s}=1.96 \) TeV, Phys. Rev. Lett. 95 (2005) 022003 [hep-ex/0412050] [INSPIRE].
D0 collaboration, B. Abbott et al., The isolated photon cross-section in \( p\overline{p} \) collisions at \( \sqrt{s}=1.8 \) TeV, Phys. Rev. Lett. 84 (2000) 2786 [hep-ex/9912017] [INSPIRE].
D0 collaboration, V.M. Abazov et al., Measurement of the isolated photon cross section in \( p\overline{p} \) collisions at \( \sqrt{s}=1.96 \) TeV, Phys. Lett. B 639 (2006) 151 [Erratum ibid. B 658 (2008) 285] [hep-ex/0511054] [INSPIRE].
ATLAS collaboration, High-E T isolated-photon plus jets production in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Nucl. Phys. B 918 (2017) 257 [arXiv:1611.06586] [INSPIRE].
ATLAS collaboration, Measurement of the cross section for inclusive isolated-photon production in pp collisions at \( \sqrt{s}=13 \) TeV using the ATLAS detector, Phys. Lett. B 770 (2017) 473 [arXiv:1701.06882] [INSPIRE].
CMS collaboration, Measurement of the triple-differential cross section for photon+jets production in proton-proton collisions at \( \sqrt{s}=7 \) TeV, JHEP 06 (2014) 009 [arXiv:1311.6141] [INSPIRE].
ZEUS collaboration, J. Breitweg et al., Observation of isolated high E(t) photons in photoproduction at HERA, Phys. Lett. B 413 (1997) 201 [hep-ex/9708038] [INSPIRE].
ZEUS collaboration, J. Breitweg et al., Measurement of inclusive prompt photon photoproduction at HERA, Phys. Lett. B 472 (2000) 175 [hep-ex/9910045] [INSPIRE].
ZEUS collaboration, S. Chekanov et al., Study of the effective transverse momentum of partons in the proton using prompt photons in photoproduction at HERA, Phys. Lett. B 511 (2001) 19 [hep-ex/0104001] [INSPIRE].
ZEUS collaboration, S. Chekanov et al., Measurement of prompt photons with associated jets in photoproduction at HERA, Eur. Phys. J. C 49 (2007) 511 [hep-ex/0608028] [INSPIRE].
H1 collaboration, A. Aktas et al., Measurement of prompt photon cross sections in photoproduction at HERA, Eur. Phys. J. C 38 (2005) 437 [hep-ex/0407018] [INSPIRE].
ZEUS collaboration, S. Chekanov et al., Observation of isolated high E(T ) photons in deep inelastic scattering, Phys. Lett. B 595 (2004) 86 [hep-ex/0402019] [INSPIRE].
ZEUS collaboration, S. Chekanov et al., Measurement of isolated photon production in deep inelastic ep scattering, Phys. Lett. B 687 (2010) 16 [arXiv:0909.4223] [INSPIRE].
H1 collaboration, F.D. Aaron et al., Measurement of isolated photon production in deep-inelastic scattering at HERA, Eur. Phys. J. C 54 (2008) 371 [arXiv:0711.4578] [INSPIRE].
ZEUS collaboration, H. Abramowicz et al., Measurement of isolated photons accompanied by jets in deep inelastic ep scattering, Phys. Lett. B 715 (2012) 88 [arXiv:1206.2270] [INSPIRE].
T. Sjöstrand et al., PYTHIA 6.4 physics and manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].
P. Aurenche, M. Fontannaz and J.P. Guillet, New NLO parametrizations of the parton distributions in real photons, Eur. Phys. J. C 44 (2005) 395 [hep-ph/0503259] [INSPIRE].
P. Aurenche and M. Fontannaz, Photon-jet correlations in deep-inelastic scattering, Eur. Phys. J. C 77 (2017) 324 [arXiv:1704.08074] [INSPIRE].
S.P. Baranov, A.V. Lipatov and N.P. Zotov, Deep inelastic prompt photon production at HERA in the k t -factorization approach, Phys. Rev. D 81 (2010) 094034 [arXiv:1001.4782] [INSPIRE].
ZEUS collaboration, U. Holm et al., The ZEUS Detector. Status Report, unpublished, DESY (1993), http://www-zeus.desy.de/bluebook/bluebook.html [INSPIRE].
N. Harnew et al., Vertex triggering using time difference measurements in the ZEUS central tracking detector, Nucl. Instrum. Meth. A 279 (1989) 290 [INSPIRE].
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 [INSPIRE].
B. Foster et al., The design and construction of the ZEUS central tracking detector, Nucl. Instrum. Meth. A 338 (1994) 254 [INSPIRE].
A. Polini et al., The design and performance of the ZEUS Micro Vertex detector, Nucl. Instrum. Meth. A 581 (2007) 656 [arXiv:0708.3011] [INSPIRE].
M. Derrick et al., Design and construction of the ZEUS barrel calorimeter., Nucl. Instrum. Meth. A 309 (1991) 77 [INSPIRE].
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 [INSPIRE].
A. Caldwell et al., Design and implementation of a high precision readout system for the ZEUS calorimeter, Nucl. Instrum. Meth. A 321 (1992) 356 [INSPIRE].
ZEUS Barrel Calorimeter Group collaboration, A. Bernstein et al., Beam tests of the ZEUS barrel calorimeter, Nucl. Instrum. Meth. A 336 (1993) 23 [INSPIRE].
J. Andruszków et al., First measurement of HERA luminosity by ZEUS lumi monitor, DESY-92-066 (1992).
ZEUS collaboration, M. Derrick et al., Measurement of total and partial photon proton cross-sections at 180 GeV center-of-mass energy, Z. Phys. C 63 (1994) 391 [INSPIRE].
ZEUS Luminosity Group collaboration, J. Andruszkow et al., Luminosity measurement in the ZEUS experiment, Acta Phys. Polon. B 32 (2001) 2025 [INSPIRE].
M. Helbich et al., The spectrometer system for measuring ZEUS luminosity at HERA, Nucl. Instrum. Meth. A 565 (2006) 572 [physics/0512153] [INSPIRE].
W.H. Smith, K. Tokushuku and L.W. Wiggers, The ZEUS trigger system, in the proceedings of Computing in High-Energy Physics (CHEP), September 21-25, Annecy, France (1992) [DESY-92-150B].
P.D. Allfrey et al., The design and performance of the ZEUS global tracking trigger, Nucl. Instrum. Meth. A 580 (2007) 1257 [INSPIRE].
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] [INSPIRE].
ZEUS collaboration, M. Derrick et al., Initial study of deep inelastic scattering with ZEUS at HERA, Phys. Lett. B 303 (1993) 183 [INSPIRE].
ZEUS collaboration, J. Breitweg et al., Measurement of the diffractive structure function F2(D(4)) at HERA, Eur. Phys. J. C 1 (1998) 81 [hep-ex/9709021] [INSPIRE].
ZEUS collaboration, J. Breitweg et al., Measurement of the diffractive cross-section in deep inelastic scattering using ZEUS 1994 data, Eur. Phys. J. C 6 (1999) 43 [hep-ex/9807010] [INSPIRE].
G.M. Briskin, Diffractive dissociation in ep deep inelastic scattering, Ph.D. Thesis, Tel Aviv University, Tel Aviv, Israel (1998) [DESY-THESIS-1998-036].
ZEUS collaboration, H. Abramowicz et al., Further studies of the photoproduction of isolated photons with a jet at HERA, JHEP 08 (2014) 023 [arXiv:1405.7127] [INSPIRE].
S. Catani, Y.L. Dokshitzer, M.H. Seymour and B.R. Webber, Longitudinally invariant K t clustering algorithms for hadron hadron collisions, Nucl. Phys. B 406 (1993) 187 [INSPIRE].
S.D. Ellis and D.E. Soper, Successive combination jet algorithm for hadron collisions, Phys. Rev. D 48 (1993) 3160 [hep-ph/9305266] [INSPIRE].
H. Spiesberger, HERACLES and DJANGOH event generators for ep interactions at HERA including radiative processes, http://wwwthep.physik.uni-mainz.de/∼hspiesb/djangoh/ djangoh.html (1998).
A. Kwiatkowski, H. Spiesberger and H.J. Mohring, HERACLES: an event generator for ep interactions at HERA energies including radiative processes: version 1.0, Comput. Phys. Commun. 69 (1992) 155 [INSPIRE].
L. Lönnblad, ARIADNE version 4: a program for simulation of QCD cascades implementing the color dipole model, Comput. Phys. Commun. 71 (1992) 15 [INSPIRE].
T. Sjöstrand, The Lund Monte Carlo for jet fragmentation and e + e − physics: JETSET version 6.2, Comput. Phys. Commun. 39 (1986) 347 [INSPIRE].
B. Andersson, G. Gustafson, G. Ingelman and T. Sjöstrand, Parton fragmentation and string dynamics, Phys. Rept. 97 (1983) 31 [INSPIRE].
R. Brun et al., GEANT3, CERN-DD/EE/84-1 (1987).
A. Gehrmann-De Ridder, G. Kramer and H. Spiesberger, Photon plus jet-cross sections in deep inelastic ep collisions at order O(α 2 α s ), Nucl. Phys. B 578 (2000) 326 [hep-ph/0003082] [INSPIRE].
A. Gehrmann-De Ridder, T. Gehrmann and E. Poulsen, Isolated photons in deep inelastic scattering, Phys. Rev. Lett. 96 (2006) 132002 [hep-ph/0601073] [INSPIRE].
A. Gehrmann-De Ridder, T. Gehrmann and E. Poulsen, Measuring the photon fragmentation function at HERA, Eur. Phys. J. C 47 (2006) 395 [hep-ph/0604030] [INSPIRE].
P. Aurenche and M. Fontannaz, Photon-jet cross sections in deep-inelastic scattering, Eur. Phys. J. C 75 (2015) 64 [arXiv:1411.4878] [INSPIRE].
M. Forrest, Isolated photon production in deep inelastic scattering at HERA, Ph.D. Thesis, University of Glasgow, Glasgow, U.K. (2010).
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ArXiv ePrint: 1712.04273
S. Antonelli, A. Bruni, M. Corradi, A. Polini, M. Capua, A. Mastroberardino, M. Schioppa, E. Tassi, A. Bertolin, S. Dusini, A. Longhin, L. Stanco, R. Brugnera, A. Garfagnini, A. Solano, M. Ruspa are supported by the Italian National Institute for Nuclear Physics (INFN)
I. Brock, E. Paul are supported by the German Federal Ministry for Education and Research (BMBF), under contract No. 05 H09PDF
Z.A. Ibrahim, N.Z. Jomhari, F. Mohamad Idris, N. Mohammad Nasir, W.A.T. Wan Abdullah are supported by HIR grant UM.C/625/1/HIR/149 and UMRG grants RU006-2013, RP012A-13AFR and RP012B-13AFR from Universiti Malaya, and ERGS grant ER004-2012A from the Ministry of Education, Malaysia
P.J. Bussey, D.H. Saxon, I.O. Skillicorn, A.M. Cooper-Sarkar, R.C.E. Devenish, C. Gwenlan, N.H. Brook, M. Wing are supported by the Science and Technology Facilities Council, U.K.
B. Foster, E. Gallo, R. Klanner, N. Kovalchuk, E. Lohrmann, J. Sztuk-Dambietz, M. Turcato are supported by the German Federal Ministry for Education and Research (BMBF), under contract No. 05h09GUF, and the SFB 676 of the Deutsche Forschungsgemeinschaft (DFG)
R. Hori, K. Nagano, K. Tokushuku, S. Yamada, Y. Yamazaki, T. Tsurugai, Y. Iga, M. Ishitsuka, M. Kuze are supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and its grants for Scientific Research
R.K. Dementiev, L.K. Gladilin, Yu.A. Golubkov, I.A. Korzhavina, B.B. Levchenko, O.Yu. Lukina, L.M. Shcheglova are partially supported by RF Presidential grant NSh-7989.2016.2
H. Abramowicz, S. Kananov, A. Levy, A. Stern are supported by the Israel Science Foundation
C.D. Catterall is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC)
V. Myronenko, O. Turkot, K. Wichmann are supported by the Alexander von Humboldt Foundation
B. Foster is Alexander von Humboldt Professor
H. Abramowicz is External Scientific Member
M. Wing is also supported by DESY and the Alexander von Humboldt Foundation
W. Perlanski is a member of Lódz University, Poland
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The ZEUS collaboration., Abramowicz, H., Abt, I. et al. Further studies of isolated photon production with a jet in deep inelastic scattering at HERA. J. High Energ. Phys. 2018, 32 (2018). https://doi.org/10.1007/JHEP01(2018)032
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DOI: https://doi.org/10.1007/JHEP01(2018)032