Prompt J = production in hadronic Z 0 decays The OPAL Collaboration

Evidence is presented for the production of prompt J= mesons (not originating in b-hadron decays) in hadronic Z decays. Using a sample of 3.6 million hadronic events, 24 prompt J= candidates are identi ed from their decays into ee and + pairs. The background is estimated to be 10:2 2:0 events. The following branching ratio for prompt J= production is obtained: Br(Z! prompt J= +X) = (1:9 0:7 0:5 0:5) 10 ; where the rst error is statistical, the second systematic and the third error accounts for uncertainties in the prompt J= production mechanism. (Submitted to Phys. Lett. B) The OPAL Collaboration G.Alexander, J. Allison, N. Altekamp, K.Ametewee, K.J. Anderson, S. Anderson, S. Arcelli, S.Asai, D.Axen, G.Azuelos, A.H.Ball, E.Barberio, R.J. Barlow, R.Bartoldus, J.R. Batley, G.Beaudoin, J.Bechtluft, C. Beeston, T.Behnke, A.N.Bell, K.W.Bell, G.Bella, S. Bentvelsen, P. Berlich, S. Bethke, O.Biebel , V.Blobel, I.J. Bloodworth, J.E.Bloomer, P. Bock, H.M.Bosch, M.Boutemeur, B.T.Bouwens, S.Braibant, R.M.Brown, H.J. Burckhart, C.Burgard, R. B urgin, P.Capiluppi , R.K. Carnegie, A.A.Carter, J.R.Carter, C.Y.Chang, C.Charlesworth, D.G.Charlton, D.Chrisman, S.L. Chu, P.E.L.Clarke, I.Cohen, J.E.Conboy, O.C.Cooke, M.Cu ani, S.Dado, C.Dallapiccola, G.M.Dallavalle , S.De Jong, L.A. del Pozo, K.Desch, M.S.Dixit, E. do Couto e Silva, M.Doucet, E.Duchovni, G.Duckeck, I.P. Duerdoth, J.E.G.Edwards, P.G.Estabrooks, H.G.Evans, M.Evans, F.Fabbri, P. Fath, F.Fiedler, M.Fierro, H.M.Fischer, R. Folman, D.G.Fong, M.Foucher, H. Fukui, A.F urtjes, P.Gagnon, A.Gaidot, J.W.Gary, J. Gascon, S.M.Gascon-Shotkin, N.I. Geddes, C.Geich-Gimbel , F.X.Gentit, T.Geralis, G.Giacomelli, P.Giacomelli , R.Giacomelli, V.Gibson, W.R.Gibson, D.M.Gingrich, J.Goldberg, M.J.Goodrick, W.Gorn, C.Grandi, E.Gross, M.Gruw e, C.Hajdu, G.G.Hanson, M.Hansroul, M.Hapke, C.K.Hargrove, P.A.Hart, C.Hartmann, M.Hauschild, C.M.Hawkes, R.Hawkings, R.J.Hemingway, G.Herten, R.D.Heuer, M.D.Hildreth , J.C.Hill , S.J.Hillier , T.Hilse, J.Hoare, P.R. Hobson, R.J.Homer, A.K.Honma, D.Horv ath, R. Howard, R.E. Hughes-Jones, D.E.Hutchcroft, P. Igo-Kemenes, D.C. Imrie, M.R. Ingram, A. Jawahery, P.W. Je reys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, G.Jones, M. Jones, R.W.L. Jones, U. Jost, P. Jovanovic, T.R. Junk, D.Karlen, K.Kawagoe, T.Kawamoto, R.K.Keeler, R.G.Kellogg, B.W.Kennedy, B.J. King, J. Kirk, S.Kluth, T.Kobayashi, M.Kobel, D.S.Koetke, T.P.Kokott, S.Komamiya, R. Kowalewski, T.Kress, P.Krieger, J. von Krogh, P. Kyberd, G.D.La erty, H. Lafoux, R. Lahmann, W.P.Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, J.G.Layter, D. Lazic, A.M.Lee, E. Lefebvre, D. Lellouch , J. Letts, L. Levinson, C. Lewis, S.L. Lloyd, F.K.Loebinger, G.D.Long, M.J. Losty, J. Ludwig, A. Luig, A.Malik, M.Mannelli, S.Marcellini , C.Markus, A.J.Martin, J.P.Martin, G.Martinez, T.Mashimo, W.Matthews, P.Mattig, W.J.McDonald, J.McKenna, E.A.Mckigney, T.J.McMahon, A.I.McNab, R.A.McPherson, F.Meijers, S.Menke, F.S.Merritt, H.Mes, J.Meyer, A.Michelini , G.Mikenberg, D.J.Miller, R.Mir, W.Mohr, A.Montanari, T.Mori, M.Morii, U.M uller, H.A.Neal, B. Nellen, B.Nijjhar, R.Nisius, S.W.O'Neale, F.G.Oakham, F.Odorici, H.O.Ogren, T.Omori, M.J.Oreglia, S. Orito, J. P alink as, J.P.Pansart, G.P asztor, J.R.Pater, G.N.Patrick, M.J.Pearce, S. Petzold, P. Pfeifenschneider, J.E.Pilcher, J. Pinfold, D.E.Plane, P.Po enberger, B. Poli, A. Posthaus, H. Przysiezniak, D.L.Rees, D.Rigby, S.A.Robins, N.Rodning, J.M.Roney, A.Rooke, E.Ros, A.M.Rossi, M.Rosvick, P.Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R.Rust, R. Rylko, E.K.G. Sarkisyan, M. Sasaki, C. Sbarra, A.D.Schaile, O. Schaile, F. Scharf, P. Schar -Hansen, P. Schenk, B. Schmitt, S. Schmitt, M. Schroder, H.C. Schultz-Coulon, M. Schulz, P. Sch utz, W.G.Scott, T.G.Shears, B.C. Shen, C.H. Shepherd-Themistocleous , P. Sherwood, G.P.Siroli , A. Sittler, A. Skillman, A. Skuja, A.M.Smith, T.J. Smith, G.A. Snow, R. Sobie, S. Soldner-Rembold , R.W.Springer, M. Sproston, A. Stahl, M. Starks, M. Steiert, K. Stephens, J. Steuerer, B. Stockhausen, D. Strom, F. Strumia, P. Szymanski, R. Ta rout, S.D.Talbot, S.Tanaka, P.Taras, S.Tarem, M.Tecchio, M.Thiergen, M.A.Thomson, E. von Torne, S. Towers, M.Tscheulin, T.Tsukamoto, E.Tsur, A.S.Turcot, M.F.Turner-Watson, P.Utzat, R.Van Kooten, G.Vasseur, M.Verzocchi, P.Vikas, M.Vincter, E.H.Vokurka, F.Wackerle, A.Wagner,