Elastic J/psi production at HERA

Summary, in English

Cross sections for elastic production of J/psi mesons in photoproduction and electroproduction are measured in electron proton collisions at HERA using an integrated luminosity of 55 pb(-1). Results are presented for photon virtualities Q(2) up to 80 GeV2. The dependence on the photon-proton centre of mass energy W-gamma p is analysed in the range 40 <= W-gamma p <= 305 GeV in photoproduction and 40 <= W-gamma p <= 160 GeV in electroproduction. The W-gamma p dependences of the cross sections do not change significantly with Q(2) and can be described by models based on perturbative QCD. Within such models, the data show a high sensitivity to the gluon density of the proton in the domain of low Bjorken x and low Q(2). Differential cross sections d sigma/dt, where t is the squared four-momentum transfer at the proton vertex, are measured in the range vertical bar t vertical bar < 1.2 GeV2 as functions of W-gamma p and Q(2). Effective Pomeron trajectories are determined for photoproduction and electroproduction. The J/psi production and decay angular distributions are consistent with s-channel helicity conservation. The ratio of the cross sections for longitudinally and transversely polarised photons is measured as a function of Q(2) and is found to be described by perturbative QCD based models.

• Author: A. Aktas; V. Andreev; T. Anthonis; B. Antunovic; S. Aplin; A. Asmone; A. Astvatsatourov; A. Babaev; S. Backovic; J. Baehr; A. Baghdasaryan; P. Baranov; E. Barrelet; W. Bartel; S. Baudrand; S. Baumgartner; J. Becker; M. Beckingham; O. Behnke; O. Behrendt; A. Belousov; C. Berger; N. Berger; J. C. Bizot; M. -O. Boenig; V. Boudry; J. Bracinik; G. Brandt; V. Brisson; D. Bruncko; F. W. Buesser; A. Bunyatyan; G. Buschhorn; L. Bystritskaya; A. J. Campbell; S. Caron; F. Cassol-Brunner; K. Cerny; V. Cerny; V. Chekelian; J. G. Contreras; J. A. Coughlan; B. E. Cox; G. Cozzika; J. Cvach; J. B. Dainton'; W. D. Dau; K. Daum; Y. de Boer; B. Delcourt; M. Del Degan; A. De Roeck; K. Desch; E. A. De Wolf; C. Diaconu; V. Dodonov; A. Dubak; G. Eckerlin; V. Efremenko; S. Egli; R. Eichler; F. Eisele; M. Ellerbrock; E. Elsen; W. Erdmann; S. Essenov; A. Falkewicz; P. J. W. Faulkner; L. Favart; A. Fedotov; R. Felst; J. Ferencei; L. Finke; M. Fleischer; P. Fleischmann; G. Flucke; A. Fomenko; I. Foresti; G. Franke; T. Frisson; E. Gabathuler; E. Garutti; J. Gayler; C. Gerlich; S. Ghazaryan; S. Ginzburgskaya; A. Glazov; I. Glushkov; L. Goerlich; M. Goettlich; N. Gogitidze; S. Gorbounov; C. Goyon; C. Grab; T. Greenshaw; M. Gregori; B. R. Grell; G. Grindhammer; C. Gwilliam; D. Haidt; L. Hajduk; Magnus Hansson; G. Heinzelmann; R. C. W. Henderson; H. Henschel; O. Henshaw; G. Herrera; M. Hildebrandt; K. H. Hiller; D. Hoffmann; R. Horisberger; A. Hovhannisyan; T. Hreus; S. Hussain; M. Ibbotson; M. Ismail; M. Jacquet; L. Janauschek; X. Janssen; V. Jemanov; Leif Jönsson; D. P. Johnson; A. W. Jung; Hannes Jung; M. Kapichine; J. Katzy; I. R. Kenyon; C. Kiesling; M. Klein; C. Kleinwort; T. Klimkovich; T. Kluge; G. Knies; Albert Knutsson; V. Korbel; P. Kostka; K. Krastev; J. Kretzschmar; A. Kropivnitskaya; K. Krueger; J. Kueckens; M. P. J. Landon; W. Lange; T. Lastovicka; G. Lastovicka-Medin; P. Laycock; A. Lebedev; G. Leibenguth; V. Lendermann; S. Levonian; L. Lindfeld; K. Lipka; A. Liptaj; B. Listo; J. List; E. Lobodzinska; N. Loktionova; R. Lopez-Fernandez; V. Lubimov; A. -I. Lucaci-Timoce; H. Lueders; D. Lueke; T. Lux; L. Lytkin; A. Makankine; N. Malden; E. Malinovski; S. Mangano; P. Marage; R. Marshall; M. Martisikova; H. -U. Martyn; S. J. Maxfield; D. Meer; A. Mehta; K. Meier; A. B. Meyer; H. Meyer; J. Meyer; S. Mikocki; I. Milcewicz-Mika; D. Milstead; D. Mladenov; A. Mohamed; F. Moreau; A. Morozov; J. V. Morris; M. U. Mozer; K. Mueller; P. Murin; K. Nankov; B. Naroska; T. Naumann; P. R. Newman; C. Niebuhr; A. Nikiforov; D. Nikitin; G. Nowak; M. Nozicka; R. Oganezov; B. Olivier; J. E. Olsson; Sakar Osman; D. Ozerov; V. Palichik; I. Panagoulias; T. Papadopoulou; C. Pascaud; G. D. Patel; M. Peez; E. Perez; D. Perez-Astudillo; A. Perieanu; A. Petrukhin; D. Pitzl; R. Placakyte; B. Portheault; B. Povh; P. Prideaux; A. J. Rahmat; N. Raicevic; P. Reimer; A. Rimmer; C. Risler; E. Rizvi; P. Robmann; B. Roland; R. Roosen; A. Rostovtsev; Z. Rurikova; S. Rusakov; F. Salvaire; D. P. C. Sankey; E. Sauvan; S. Schaetzel; F. -P. Schilling; D. Schmidt; S. Schmidt; S. Schmitt; C. Schmitz; L. Schoeffel; A. Schoening; H. -C. Schultz-Coulon; K. Sedlak; F. Sefkow; R. N. Shaw-West; I. Sheviakov; L. N. Shtarkov; T. Sloan; P. Smirnov; Y. Soloviev; D. South; V. Spaskov; A. Specka; B. Stella; J. Stiewe; I. Strauch; U. Straumann; V. Tchoulakov; G. Thompson; P. D. Thompson; F. Tomasz; D. Traynor; P. Truoel; I. Tsakov; G. Tsipolitis; I. Tsurin; J. Turnau; E. Tzamariudaki; M. Urban; A. Usik; D. Utkin; A. Valkarova; C. Vallee; P. Van Mechelen; A. Vargas Trevino; Y. Vazdik; C. Veelken; A. Vest; S. Vinokurova; V. Volchinski; K. Wacker; J. Wagner; G. Weber; R. Weber; D. Wegener; C. Werner; M. Wessels; B. Wessling; C. Wigmore; C. Wissing; R. Wolf; E. Wuensch; S. Xella; W. Yan; V. Yeganov; J. Zacek; J. Zalesak; Z. Zhang; A. Zhelezov; A. Zhokin; Y. C. Zhu; J. Zimmermann; T. Zimmermann; H. Zohrabyan; F. Zomer
• Department/s: Particle and nuclear physics
• Publishing year: 2006
• Language: English
• Pages: 585-603
• Publication/Series: European Physical Journal C. Particles and Fields
• Volume: 46
• Issue: 3
• Links: http://dx.doi.org/10.1140/epjc/s2006-02519-5
• Document type: Journal article
• Publisher: Springer
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1434-6044