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
1993-01-01

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.
1993
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. BUSS...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/108492
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