Observation of a fully reconstructed [formula omitted] pair with long proper lifetimes in a high resolution hydrogen bubble chamber and the European hybrid spectrometer

• Published in: Physics letters. B 1981-06, Vol.102 (4), p.285-290
• Main Authors: Adeva, B., Aguilar-Benitez, M., Allison, W., Bagnaia, P., Baldo, B., Barone, L., Bartl, W., Bergier, A., Bettini, A., Bizzarri, R., Boratav, M., Borreani, G., Bruyant, F., Castelli, E., Checchia, P., Chliapnikov, P., Ciapetti, G., Cooremans-Bertrand, G., Crennel, D., Cresti, M., Crijns, F., Dibon, H., Di Capua, E., Dionisi, C., Dolbeau, J., Dumarchez, J., Etienne, F., Ferrando, A., Fisher, C., Frühwirth, R., Gatignon, L., Grard, F., Hartjes, F., Herquet, P., Hervé, A., Holmgren, S., Hrubec, J., Hughes, P., Johansson, E., Kesteman, J., Kistenev, E., Kittel, W., Kuhn, D., Kurtz, N., Ladron De Guevara, P., Lecoq, P., Lemonne, J., Lesceux, J., Leutz, H., Lipari, P., Loverre, P., Marchetto, F., Marin, J., Markytan, M., Marzano, F., Mazzucato, M., Menichetti, E., Michalon-Mentzer, M., Michalon, A., Moa, T., Montanet, L., Neuhofer, G., Nguyen, H., Nilsson, S., Paler, K., Pascoli, D., Peruzzo, L., Pilette, P., Piredda, G., Poljakov, B., Poppleton, A., Poropat, P., Porth, P., Regler, M., Reucroft, S., Robb, L., Rossi, P., Rubio, J., Sartori, G., Sessa, M., Stergiou, A., Subramanian, A., Tavernier, S., Toet, D., Touboul, M., Touchard, A., Troncon, C., Van Immerseel, M., Ventura, L., Vilain, P., Voltolini, C., Wickens, J., Zanello, D., Zanello, L., Zholobov, G., Zotto, P., Zumerle, G.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(81)90877-7

In an experiment with 360 GeV/ c π − beam at the CERN SPS using the high resolution hydrogen bubble chamber LEBC and the European Hybrid Spectrometer, an event has been observed of the type π − p→ D 0 D 0 + 8 prongs. The fully reconstructed decay modes are D 0→ K −π +π 0π 0 and D 0→ K +π +π −π − , with all six charged tracks being detected in the spectrometer and all four photons from the π 0 decays detected in the lead glass gamma detection system. The D 0 has momentum 119.0 ± 0.6 GeV/ c, x F = 0.31, length 4.1 ± 0.1 mm and proper lifetime (2.1 ± 0.1) × 10 −13 s. The D 0 has momentum 78.5 ± 0.3 GeV/ c, x F = 0.19, length 7.5 ± 0.1 mm and proper lifetime (5.9 ± 0.1) × 10 −13 s.