Eur. Phys. J. A (2006) 28: 11-17
https://doi.org/10.1140/epja/i2006-10010-4

Nuclear Structure and Reactions

Resonant behaviour in double charge exchange reaction of πmesons on the nuclear photoemulsion

¹ Joint Institute for Nuclear Research Dubna, 141980, Moscow region, Russia
² Dipartimento di Fisica Generale “A. Avogadro”, Università  di Torino and INFN Sezione di Torino, I-10125, Torino, Italy
³ A.I. Alikhanov Institute of Theoretical and Experimental Physics, 117218, Moscow, Russia
⁴ Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy

^* e-mail: balestra@to.infn.it

Received: 10 January 2006
Accepted: 11 April 2006
Published online: 10 May 2006

Abstract

The invariant-mass spectra of the ppπ^- and pp systems produced in the double charge exchange (DCX) of positively charged pions on photoemulsion are analysed. A pronounced peak is observed in the ppπ^- invariant-mass spectrum, while the M_pp spectrum exhibits a strong Migdal-Watson effect of the proton-proton final-state interaction. These findings are in favor of the NN-decoupled NNπ pseudoscalar resonance with T = 0 called d'.