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 (p)over-bar+d-]pi-+p With the Obelix Spectrometer At Lear

BALESTRA, Ferruccio;BONAZZOLA, Giancarlo;BRESSANI, Tullio;BUSSA, Maria Pia;BUSSO, Luigi;COSTA, Sergio;FERRERO, Livio;GARFAGNINI, Raffaello;GRASSO, Antonino;MARCELLO, Simonetta;PANZIERI, Daniele;PIRAGINO, Guido;ZOSI, Gianfranco
1993

Abstract

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.
562
617
643
antiproton-He-4 annihilation; Pontecorvo reactions
V. G. ABLEEV;A. ADAMO;M. AGNELLO;F. BALESTRA;G. BENDISCIOLI;A. BERTIN;P. BOCCACCIO;G. BONAZZOLA;T. BRESSANI;M. BRUSCHI;M. P. BUSSA;L. BUSSO;D. CALVO;M. CAPPONI;P. CERELLO;C. CICALO;M. CORRADINI;S. COSTA;S. DECASTRO;F. DISEP;A. DONZELLA;I. V. FALOMKIN;L. FAVA;A. FELICIELLO;L. FERRERO;A. FILIPPI;V. FILIPPINI;D. GALLI;R. GARFAGNINI;U. GASTALDI;P. GIANOTTI;A. GRASSO;C. GUARALDO;F. IAZZI;A. LANARO;E. L. RIZZINI;M. LOMBARDI;V. LUCHERINI;A. MAGGIORA;G. MANEVA;S. MARCELLO;U. MARCONI;G. V. MARGAGLIOTTI;G. MARON;A. MASONI;I. MASSA;B. MINETTI;P. MONTAGNA;M. MORANDO;F. NICHITIU;D. PANZIERI;G. PAULI;M. PICCININI;G. PIRAGINO;M. POLI;G. B. PONTECORVO;G. PUDDU;R. A. RICCI;E. ROSSETTO;A. ROTONDI;A. M. ROZHDESTVENSKY;P. SALVINI;L. SANTI;M. G. SAPOZHNIKOV;N. S. CESARI;S. SERCI;R. SPIGHI;P. TEMNIKOV;S. TESSARO;F. TOSELLO;V. I. TRETYAK;G. USAI;L. VANNUCCI;S. VECCHI;G. VEDOVATO;L. VENTURELLI;M. VILLA;A. VITALE;A. ZENONI;A. ZOCCOLI;G. ZOSI
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/108492
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