Scaled momentum distributions of charged particles in dijet photoproduction at HERA
نویسندگان
چکیده
The scaled momentum distributions of charged particles in jets have been measured for dijet photoproduction with the ZEUS detector at HERA using an integrated luminosity of 359 pb. The distributions are compared to predictions based on perturbative QCD carried out in the framework of the modified leading-logarithmic approximation (MLLA) and assuming local parton-hadron duality (LPHD). The universal MLLA scale, Λeff , and the LPHD parameter, κ , are extracted. 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 P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini INFN Bologna, Bologna, Italy e S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi University and INFN Bologna, Bologna, Italy e D. Bartsch, I. Brock, H. Hartmann, E. Hilger, H.-P. Jakob, M. Jüngst, A.E. Nuncio-Quiroz, E. Paul, 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 H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom m M. Kaur, P. Kaur, I. Singh Panjab University, Department of Physics, Chandigarh, India M. Capua, S. Fazio, A. Mastroberardino, M. Schioppa, G. Susinno, E. Tassi Calabria University, Physics Department and INFN, Cosenza, Italy e J.Y. Kim Chonnam National University, Kwangju, South Korea Z.A. Ibrahim, F. Mohamad Idris, 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, USA o J. Chwastowski, A. Eskreys, J. Figiel, A. Galas, K. Olkiewicz, B. Pawlik, 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
منابع مشابه
Particle spectra at ZEUS
Charged multiplicity distributions and the mean charged multiplicity have been investigated in inclusive neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 38.6pb −1. The measurements were performed in the current region of the Breit frame, as well as in the current fragmentation region of the hadronic center-of-mass frame. The KNO-scal...
متن کاملInclusive transverse momentum distributions of charged particles in diffractive and non–diffractive photoproduction at HERA
Inclusive transverse momentum spectra of charged particles in photoproduction events in the laboratory pseudorapidity range −1.2 < η < 1.4 have been measured up to pT = 8 GeV using the ZEUS detector. Diffractive and non–diffractive reactions have been selected with an average γp centre of mass (c.m.) energy of 〈W 〉 = 180GeV. For diffractive reactions, the pT spectra of the photon dissociation e...
متن کاملMeasurement of beauty photoproduction using decays into muons in dijet events at HERA
Beauty photoproduction in dijet events has been measured at HERA with the ZEUS detector using an integrated luminosity of 126 pb −1. Beauty was identified in events with a muon in the final state by using the transverse momentum of the muon relative to the closest jet. Lifetime information from the silicon vertex detector was also used; the impact parameter of the muon with respect to the prima...
متن کاملDiffractive Dijet Production at HERA
We present recent experimental data from the H1 and ZEUS Collaborations at HERA for diffractive dijet production in deep-inelastic scattering (DIS) and photoproduction and compare them with next-to-leading order (NLO) QCD predictions using diffractive parton densities. While good agreement is found for DIS, the dijet photoproduction data are overestimated by the NLO theory, showing that factori...
متن کاملUnintegrated gluon distributions in D∗± and dijet associated photoproduction at HERA
We consider the photoproduction of D mesons associated with two hadron jets at HERA collider in the framework of the kT -factorization approach. The unintegrated gluon densities in a proton are obtained from the full CCFM, from unified BFKL-DGLAP evolution equations as well as from the Kimber-Martin-Ryskin prescription. Resolved photon contributions are reproduced by the initial-state gluon rad...
متن کامل