Inclusive Production of D ∗ ± Mesons in Photon-Photon Collisions at √ s ee = 183 and 189 GeV and a First Measurement of F γ 2 , c The OPAL Collaboration

The inclusive production of D mesons in photon-photon collisions has been measured using the OPAL detector at LEP at ee centre-of-mass energies √ see of 183 and 189 GeV. The D ∗+ mesons are reconstructed in their decay to Dπ with the D observed in the two decay modes Kπ and Kπππ. After background subtraction, 100.4 ± 12.6 (stat) D mesons have been selected in events without observed scattered beam electron (“anti-tagged”) and 29.8 ± 5.9 (stat) D mesons in events where one beam electron is scattered into the detector (“singletagged”). Direct and single-resolved events are studied separately. Differential cross-sections dσ/dp ∗ T and dσ/d|ηD ∗| as functions of the D transverse momentum p∗ T and pseudorapidity η ∗ are presented in the kinematic region 2 GeV < p ∗ T < 12 GeV and |ηD ∗| < 1.5. They are compared to next-to-leading order (NLO) perturbative QCD calculations. The total crosssection for the process e+e−→ eecc where the charm quarks are produced in the collision of two quasi-real photons is measured to be σ(ee → eecc̄) = 842 ± 97 (stat) ± 75 (sys) ± 196 (extrapolation) pb. A first measurement of the charm structure function F γ 2,c of the photon is performed in the kinematic range 0.0014 < x < 0.87 and 5 GeV < Q < 100 GeV, and the result is compared to a NLO perturbative QCD calculation. (To be submitted to Eur. Phys. J. C) The OPAL Collaboration G.Abbiendi, K.Ackerstaff, P.F.Akesson, G.Alexander, J. Allison, K.J.Anderson, S.Arcelli, S.Asai, S.F.Ashby, D.Axen, G.Azuelos, I. Bailey, A.H.Ball, E. Barberio, T.Barillari, R.J. Barlow, J.R.Batley, S. Baumann, T.Behnke, K.W.Bell, G.Bella, A.Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O.Biebel, A.Biguzzi, I.J. Bloodworth, P. Bock, J. Böhme, O.Boeriu, D.Bonacorsi, M.Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M.Brown, H.J. Burckhart, P.Capiluppi, R.K.Carnegie, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, D.Chrisman, C.Ciocca, P.E.L.Clarke, E.Clay, I. Cohen, J.E.Conboy, O.C.Cooke, J. Couchman, C.Couyoumtzelis, R.L.Coxe, M.Cuffiani, S.Dado, G.M.Dallavalle, S.Dallison, R.Davis, A. de Roeck, P.Dervan, K.Desch, B.Dienes, M.S.Dixit, M.Donkers, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, P.G.Estabrooks, E. Etzion, F. Fabbri, A. Fanfani, M.Fanti, A.A. Faust, L. Feld, P. Ferrari, F. Fiedler, M.Fierro, I. Fleck, A. Frey, A. Fürtjes, D.I. Futyan, P.Gagnon, J.W.Gary, G.Gaycken, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, D.M.Gingrich, D.Glenzinski, J.Goldberg, W.Gorn, C.Grandi, K.Graham, E.Gross, J.Grunhaus, M.Gruwé, C.Hajdu G.G.Hanson, M.Hansroul, M.Hapke, K.Harder, A.Harel, C.K.Hargrove, M.Harin-Dirac, M.Hauschild, C.M.Hawkes, R.Hawkings, R.J.Hemingway, G.Herten, R.D.Heuer, M.D.Hildreth, J.C.Hill, P.R.Hobson, A.Hocker, K.Hoffman, R.J.Homer, A.K.Honma, D.Horváth, K.R.Hossain, R.Howard, P.Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, N.Kanaya, J.Kanzaki, G.Karapetian, D.Karlen, V.Kartvelishvili, K.Kawagoe, T.Kawamoto, P.I.Kayal, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, D.H.Kim, A.Klier, T.Kobayashi, M.Kobel, T.P.Kokott, M.Kolrep, S.Komamiya, R.V.Kowalewski, T.Kress, P.Krieger, J. von Krogh, T.Kuhl, M.Kupper, P.Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, I. Lawson, J.G. Layter, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W.Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A.Macchiolo, A.Macpherson, W.Mader, M.Mannelli, S.Marcellini, T.E.Marchant, A.J.Martin, J.P.Martin, G.Martinez, T.Mashimo, P.Mättig, W.J.McDonald, J.McKenna, E.A.Mckigney, T.J.McMahon, R.A.McPherson, F.Meijers, P.Mendez-Lorenzo, F.S.Merritt, H.Mes, I.Meyer, A.Michelini, S.Mihara, G.Mikenberg, D.J.Miller, W.Mohr, A.Montanari, T.Mori, K.Nagai, I. Nakamura, H.A.Neal , R.Nisius, S.W.O’Neale, F.G.Oakham, F.Odorici, H.O.Ogren, A.Okpara, M.J.Oreglia, S.Orito, G. Pásztor, J.R.Pater, G.N.Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider , J.E. Pilcher, J. Pinfold, D.E.Plane, B. Poli, J. Polok, M.Przybycień, A.Quadt, C.Rembser, H.Rick, S.A.Robins, N.Rodning, J.M.Roney, S. Rosati, K.Roscoe, A.M.Rossi, Y.Rozen, K.Runge, O.Runolfsson, D.R.Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick , W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D.Talbot, P.Taras, S. Tarem, R.Teuscher, M.Thiergen, J. Thomas,