Measurements of the (anti)p-D annihilation at rest

Ableev, V. G.; Agnello, M.; Balestra, F.; Bendiscioli, G.; Bertin, A.; Boccaccio, P.; Botta, E.; Bressani, T.; Bruschi, M.; Bussa, M. P.; Busso, L.; Calvo, D.; Capponi, M.; Cereda, B.; Cerello, P.; Cicaló, C.; Costa, S.; De Castro, S.; Denisov, O. Y. U.; D'Isep, D.; Donzella, A.; Fava, L.; Feliciello, A.; Ferrero, L.; Filippi, A.; Filippini, V.; Fontana, A.; Galli, D.; Garfagnini, R.; Gastaldi, U.; Giacobbe, B.; Gianotti, P.; Gorchakov, O. E.; Grasso, A.; Guaraldo, C.; Iazzi, F.; Lanaro, A.; Lodi Rizzini, E.; Lombardi, M.; Lucherini, V.; Maggiora, A.; Maneva, G.; Marcello, S.; Marconi, U.; Margagliotti, Giacomo; Maron, G.; Masoni, A.; Minetti, B.; Montagna, P.; Morando, M.; Nichitiu, F.; Panzieri, D.; Pauli, G.; Piccinini, M.; Poli, M.; Prakhov, S. N.; Puddu, G.; Ricci, R. A.; Rossetto, E.; Rotondi, A.; Roshdestvensky, A. M.; Saino, A.; Salvini, P.; Santi, L.; Sapozhnikov, M. G.; Semprini Cesari, N.; Serci, S.; Spighi, R.; Temnikov, P. P.; Tessaro, S.; Tosello, F.; Tretyak, V. I.; Usai, G.; Vannucci, L.; Vecchi, S.; Vedovato, G.; Venturelli, L.; Villa, M.; Vitale, A.; Zenoni, A.; Zoccoli, A.; Zosi, G.

doi:10.1016/0375-9474(94)00523-P

The measurement of different reactions of (p) over bar d annihilation at rest in a gaseous target has been performed using the OBELIX spectrometer at LEAR (CERN). A strong deviation from the OZI-rule prediction was found from the measurement of the ratio R = phi pi/omega pi in two regions of proton momenta, P < 200 MeV/c and P > 400 MeV/c: R(phi pi(-)/omega pi(-)) = (133 +/- 26) x 10(-3) and (113 +/- 30)x 10(-3), respectively. These values are about 30 times greater than the theoretical prediction. For the first time the excitation of the Delta-resonance was observed among the final-state products of (p) over bar d annihilation. The existence of a broad enhancement in the 4 pi invariant mass at m approximate to 1480 MeV, seen in previous experiments, was confirmed. A approximate to 100 MeV downward shift of the bump position, when the proton momentum increased up to P > 400 MeV/c, was also observed, while the positions of omega, rho and f(2)(1270) did not change with the proton momentum.

Measurements of the (anti)p-D annihilation at rest / V. G., A., M., A., F., B., G., B., A., B., P., B., E., B., T., B., M., B., M. P., B., L., B., D., C., M., C., B., C., P., C., C., C., S., C., S., D.C., Denisov, O.Y.u., D., D., et al.. - In: NUCLEAR PHYSICS. A. - ISSN 0375-9474. - STAMPA. - 585:(1995), pp. 577-617. [10.1016/0375-9474(94)00523-P]