Experimental evidence for double-pomeron exchange at ISR energies

• Published in: Physics letters. B Vol. 68; no. 4; pp. 385 - 388
• Main Authors: De Kerret, H., Kwak, N., Nagy, E., Orr, R.S., Regler, M., Schmidt-Parzefall, W., Schubert, K.R., Winter, K., Brandt, A., Büsser, F.W., Dibon, H., Flügge, G., Niebergall, F., Schumacher, P.E., Aubert, J.J., Broll, C., Coignet, G., Favier, J., Massonnet, L, Vivargent, M., Bartl, W., Eichinger, H., Gottfried, Ch, Neuhofer, G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1977; Elsevier
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(77)90500-7

Studying the reaction pp → pp π + π − at s = 23 GeV and 45 GeV at the CERN ISR we have found an experimental definition of a new class of diffractive events which we attribute to double-Pomeron exchange. The correlation of the quasi-elastically scattered protons, the energy dependence of the cross section, and the angular momentum of the ( π + π −) state are analysed and found to be in agreement with theoretical expectations for double-Pomeron exchange.