A new measurement of the Pontecorvo reaction with the OBELIX spectrometer at LEAR

Ableev, V. G.; Adamo, A.; Agnello, M.; Balestra, F.; Bendiscioli, G.; Bertin, A.; Boccaccio, P.; Bonazzola, G.; Bressani, T.; Bruschi, M.; Bussa, M. P.; Busso, L.; Calvo, D.; Capponi, M.; Cerello, P.; Cicalò, C.; Corradini, M.; Costa, S.; De Castro, S.; D'Isep, F.; Donzella, A.; Falomkin, I. V.; Fava, L.; Feliciello, A.; Ferrero, L.; Filippi, A.; Filippini, V.; Galli, D.; Garfagnini, R.; Gastaldi, U.; Gianotti, P.; Grasso, A.; Guaraldo, C.; Lazzi, F.; Lanaro, A.; Lodi Rizzini, E.; Lombardi, M.; Lucherini, V.; Maggiora, A.; Maneva, G.; Marcello, S.; Marconi, U.; Margagliotti, Giacomo; Maron, G.; Masoni, A.; Massa, I.; Minetti, B.; Montagna, P.; Morando, M.; Nichitiu, F.; Panzieri, D.; Pauli, G.; Piccinini, M.; Piragino, G.; Poli, M.; Pontecorvo, G. B.; Puddu, G.; Ricci, R. A.; Rossetto, E.; Rotondi, A.; Rozhdestvensky, A. M.; Salvini, P.; Santi, L.; Sapozhnikov, M. G.; Semprini Cesari, N.; Serci, S.; Spighi, R.; Temnikov, 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(93)90132-H

Antinucleon-nucleus annihilations into two-body final states containing only one or no meson are unusual annihilations (Pontecorvo reactions), practically unexplored experimentally, with the exception of the channel pBAR d --> pi- p, for which only two low-statistics measurements exist. Their physical interest lies in the possibility of exploring small-distance nuclear dynamics, in which an important role can be played by non-nucleonic degrees of freedom. A new measurement of the pBAR d --> pi- p reaction rate at rest, performed with the OBELIX spectrometer at LEAR, with the best statistics up to now and a careful evaluation of systematic effects is reported, together with a critical analysis of the existing theoretical models. The measured branching ratio, which confirms the previous results, can represent a reference point for the studies in the field.

A new measurement of the Pontecorvo reaction with the OBELIX spectrometer at LEAR / V. G., A., A., A., M., A., F., B., G., B., A., B., P., B., G., B., T., B., M., B., M. P., B., L., B., D., C., M., C., P., C., C., C., M., C., S., C., S., D.C., F., D., et al.. - In: NUCLEAR PHYSICS. A. - ISSN 0375-9474. - STAMPA. - 562:(1993), pp. 617-643. [10.1016/0375-9474(93)90132-H]