The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons has been studied using data taken at √ see = 183GeV and 189GeV with the OPAL detector at LEP. Results are presented for pp̄ invariant masses, W , in the range 2.15 < W < 3.95GeV. The cross-section measurements are compared with previous data and with recent analytic calculations based on the quark-diquark model. (To be submitted to Eur. Phys. J. C.) The OPAL Collaboration G.Abbiendi, C.Ainsley, P.F. Åkesson, G.Alexander, J. Allison, P.Amaral, G.Anagnostou, K.J.Anderson, S.Arcelli, S.Asai, D.Axen, G.Azuelos, I. Bailey, E. Barberio, T.Barillari, R.J. Barlow, R.J. Batley, P. Bechtle, T.Behnke, K.W.Bell, P.J. Bell, G.Bella, A.Bellerive, G.Benelli, S. Bethke, O.Biebel, I.J. Bloodworth, O.Boeriu, P. Bock, D.Bonacorsi, M.Boutemeur, S. Braibant, L. Brigliadori, R.M.Brown, K.Buesser, H.J. Burckhart, S. Campana, R.K.Carnegie, B.Caron, A.A.Carter, J.R.Carter, C.Y.Chang, D.G.Charlton, A.Csilling , M.Cuffiani, S.Dado, G.M.Dallavalle, S.Dallison, A.De Roeck, E.A.De Wolf, K.Desch, B.Dienes, M.Donkers, J.Dubbert, E.Duchovni, G.Duckeck, I.P.Duerdoth, E. Elfgren, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, P.Gagnon, J.W.Gary, G.Gaycken, C.Geich-Gimbel, G.Giacomelli, P.Giacomelli, M.Giunta, J.Goldberg, E.Gross, J.Grunhaus, M.Gruwé, P.O.Günther, A.Gupta, C.Hajdu, M.Hamann, G.G.Hanson, K.Harder, A.Harel, M.Harin-Dirac, M.Hauschild, J. Hauschildt, C.M.Hawkes, R.Hawkings, R.J.Hemingway, C.Hensel, G.Herten, R.D.Heuer, J.C.Hill, K.Hoffman, R.J.Homer, D.Horváth, R.Howard, P.Hüntemeyer, P. Igo-Kemenes, K. Ishii, H. Jeremie, P. Jovanovic, T.R. Junk, N.Kanaya, J.Kanzaki, G.Karapetian, D.Karlen, V.Kartvelishvili, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, D.H.Kim, K.Klein, A.Klier, S.Kluth, T.Kobayashi, M.Kobel, S.Komamiya, L.Kormos, R.V.Kowalewski, T.Krämer, T.Kress, P.Krieger, J. von Krogh, D.Krop, K.Kruger, M.Kupper, G.D. Lafferty, H. Landsman, D. Lanske, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, S.L. Lloyd, F.K. Loebinger, J. Lu, J. Ludwig, A.Macpherson, W.Mader, S.Marcellini, T.E.Marchant, A.J.Martin, J.P.Martin, G.Masetti, T.Mashimo, P.Mättig, W.J.McDonald, J.McKenna, T.J.McMahon, R.A.McPherson, F.Meijers, P.Mendez-Lorenzo, W.Menges, F.S.Merritt, H.Mes, A.Michelini, S.Mihara, G.Mikenberg, D.J.Miller, S.Moed, W.Mohr, T.Mori, A.Mutter, K.Nagai, I. Nakamura, H.A.Neal, R.Nisius, S.W.O’Neale, A.Oh, A.Okpara, M.J.Oreglia, S.Orito, C. Pahl, G. Pásztor, J.R. Pater, G.N.Patrick, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, M.Przybycień, A.Quadt, K.Rabbertz, C.Rembser, P.Renkel, H.Rick, J.M.Roney, S. Rosati, Y.Rozen, K.Runge, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan , A.D. Schaile, O. Schaile, P. Scharff-Hansen, J. Schieck, T. Schoerner-Sadenius, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster , T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G. Siroli, A. Skuja, A.M. Smith, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, S. Tarem, M.Tasevsky , R.J. Taylor, R.Teuscher, M.A.Thomson, E.Torrence, D.Toya, P.Tran, T.Trefzger, A.Tricoli, I. Trigger, Z. Trócsányi, E.Tsur, M.F.Turner-Watson, I. Ueda, B.Ujvári, B.Vachon, C.F.Vollmer, P.Vannerem, M.Verzocchi, H.Voss, J. Vossebeld, D.Waller, C.P.Ward, D.R.Ward, P.M.Watkins, A.T.Watson, N.K.Watson, P.S.Wells, T.Wengler, N.Wermes, D.Wetterling G.W.Wilson, J.A.Wilson, G.Wolf, T.R.Wyatt, S.Yamashita, D. Zer-Zion, L. Zivkovic
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