0 M ar 2 00 7 DESY – 07 – 039 March 2007 Diffractive Photoproduction of D ∗ ± ( 2010 ) at HERA ZEUS
نویسندگان
چکیده
Diffractive photoproduction of D(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb. The D mesons were reconstructed in the kinematic range: transverse momentum pT (D ) > 1.9GeV and pseudorapidity |η(D∗)| < 1.6, using the decay D → Dπ s followed by D → Kπ (+c.c.). Diffractive events were identified by a large gap in pseudorapidity between the produced hadronic state and the outgoing proton. Cross sections are reported for photon-proton centre-ofmass energies in the range 130 < W < 300GeV and for photon virtualities Q < 1GeV, in two ranges of the Pomeron fractional momentum xIP < 0.035 and xIP < 0.01. The relative contribution of diffractive events to the inclusive D(2010) photoproduction cross section is about 6%. The data are in agreement with perturbative QCD calculations based on various parameterisations of diffractive parton distribution functions. The results are consistent with diffractive QCD factorisation. The ZEUS Collaboration S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida Argonne National Laboratory, Argonne, Illinois 60439-4815, USA n M.C.K. Mattingly Andrews University, Berrien Springs, Michigan 49104-0380, USA M. Jechow, N. Pavel , A.G. Yagües Molina Institut für Physik der Humboldt-Universität zu Berlin, Berlin, Germany S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, G. Sartorelli, A. Zichichi University and INFN Bologna, Bologna, Italy e D. Bartsch, I. Brock, S. Goers, H. Hartmann, E. Hilger, H.-P. Jakob, M. Jüngst, O.M. Kind, E. Paul, R. Renner, U. Samson, V. Schönberg, R. Shehzadi, M. Wlasenko Physikalisches Institut der Universität Bonn, Bonn, Germany b N.H. Brook, G.P. Heath, J.D. Morris, T. Namsoo H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom m M. Capua, S. Fazio, A. Mastroberardino, M. Schioppa, G. Susinno, E. Tassi Calabria University, Physics Department and INFN, Cosenza, Italy e J.Y. Kim, K.J. Ma Chonnam National University, Kwangju, South Korea g Z.A. Ibrahim, B. Kamaluddin, W.A.T. Wan Abdullah Jabatan Fizik, Universiti Malaya, 50603 Kuala Lumpur, Malaysia r Y. Ning, Z. Ren, F. Sciulli Nevis Laboratories, Columbia University, Irvington on Hudson, New York 10027 o J. Chwastowski, A. Eskreys, J. Figiel, A. Galas, M. Gil, K. Olkiewicz, P. Stopa, L. Zawiejski The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland i L. Adamczyk, T. Bo ld, I. Grabowska-Bo ld, D. Kisielewska, J. Lukasik, M. Przybycień, L. Suszycki Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Cracow, Poland p A. Kotański, W. S lomiński Department of Physics, Jagellonian University, Cracow, Poland
منابع مشابه
6 v 2 1 0 M ay 2 00 7 DESY – 07 – 039 March 2007 Diffractive Photoproduction of D ∗ ± ( 2010 ) at HERA ZEUS
Diffractive photoproduction of D(2010) mesons was measured with the ZEUS detector at the ep collider HERA, using an integrated luminosity of 78.6 pb. The D mesons were reconstructed in the kinematic range: transverse momentum pT (D ) > 1.9GeV and pseudorapidity |η(D∗)| < 1.6, using the decay D → Dπ s followed by D → Kπ (+c.c.). Diffractive events were identified by a large gap in pseudorapidity...
متن کامل00 3 v 1 6 S ep 1 99 6 Study of Elastic ρ 0 Photoproduction at HERA using the ZEUS Leading Proton Spectrometer
The differential cross section dσ/dt for elastic ρ photoproduction, γp → ρp (ρ → π+π−), has been measured in ep interactions at HERA. The squared four-momentum exchanged at the proton vertex, t, has been determined directly by measuring the momentum of the scattered proton using the ZEUS Leading Proton Spectrometer (LPS), a large scale system of silicon micro-strip detectors operating close to ...
متن کاملDiffractive PDFs and factorisation tests at HERA
The HERA collider at DESY (Hamburg) has provided Deep Inelastic Scattering (DIS) of electrons off protons in the years 1992-2007 for the H1 and ZEUS experiments with a centre of mass energy up to 318 GeV. Diffractive dissociation of photons in the reaction γ(∗) p → X p, constitute a large fraction (∼ 10%) of the visible cross section in deep inelastic scattering (DIS), and the process can be se...
متن کاملar X iv : h ep - e x / 95 05 00 1 v 1 3 M ay 1 99 5 Study of the Photon Remnant in Resolved Photoproduction at HERA ZEUS
Photoproduction at HERA is studied in ep collisions, with the ZEUS detector, for γp centre-of-mass energies ranging from 130-270 GeV. A sample of events with two high-pT jets (pT > 6 GeV, η < 1.6) and a third cluster in the approximate direction of the electron beam is isolated using a clustering algorithm. These events are mostly due to resolved photoproduction. The third cluster is identified...
متن کاملMeasurement of D∗± diffractive cross sections in photoproduction at HERA
The first measurement of D∗± meson diffractive photoproduction cross sections has been performed with the ZEUS detector at the HERA ep collider, using an integrated luminosity of 38 pb−1. The measurement has been performed for photon– proton center-of-mass energies in the range 130 < W < 280 GeV and photon virtualities Q2 < 1 GeV2. D∗± mesons have been reconstructed with p ∗ T > 2 GeV and −1.5 ...
متن کامل