Observation of hard processes in collisions of two quasi-real photons

• Published in: Physics letters. B Vol. 138; no. 1; pp. 219 - 224
• Main Authors: Althoff, M., Braunschweig, W., Kirschfink, F.J., Lübelsmeyer, K., Martyn, H.-U., Peise, G., Rimkus, J., Rosskamp, P., Sander, H.G., Schmitz, D., Siebke, H., Wallraff, W., Fischer, H.M., Hartmann, H., Hillen, W., Jocksch, A., Knop, G., Köpke, L., Kolanoski, H., Kück, H., Mertens, V., Wedemeyer, R., Wermes, N., Wollstadt, M., Eisenberg, Y., Gather, K., Hultschig, H., Joos, P., Koch, W., Kötz, U., Kowalsi, H., Ladage, A., Lüke, D., Mättig, P., Notz, D., Pyrlik, J., Quarrie, D.R., Rushton, M., Schütte, W., Trines, D., Wolf, G., Xiao, Ch, Fohrmann, R., Hilger, E., Krasemann, H.L., Leu, P., Pandoulas, D., Poelz, G., Wiik, B.H., Beuselinck, R., Binnie, D.M., Campbell, A.L., Dornan, P.J., Foster, B., Jenkins, C., Jones, T.D., Jones, W.G., McCardle, J., Sedgbeer, J.K., Thomas, J., Wan Abdullah, W.A.T., Bell, K.W., Bowler, M.G., Bull, P., Cashmore, R.J., Clarke, P.E.L., Devenish, R., Hawkes, C.M., Lloyd, S.L., Salmon, G.L., Youngman, C., Forden, G.E., Hart, J.C., Harvey, J., Hasell, D.K., Proudfoot, J., Saxon, D.H., Woodworth, P.L., Barreiro, F., Dittmar, M., Neumann, B., Duchovni, E., Karshon, U., Mikenberg, G., Mir, R., Revel, D., Ronat, E., Shapira, A., Yekutieli, G., Barklow, T., Caldwell, A., Cherney, M., Izen, J.M., Mermikides, M., Rudolph, G., Strom, D., Venkataramania, H., Wicklund, E., Wu, Sau Lan, Zobernig, G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 12.04.1984
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(84)91904-X

Hard processes in photon-photon collisions are studied using high statistics data without requiring an electron tag. A high yield of hadrons with p t in the range 1.5–3.0 GeV/ c is observed. This yield exceeds the expectation of the Born term by a factor of four.