https://doi.org/10.1140/epja/i2018-12641-0
Regular Article - Experimental Physics
Resonance-like coherent production of a pion pair in the reaction 
in the GeV region
1
Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, RU-141980, Dubna, Russia
2
Institut für Kernphysik, Forschungszentrum Jülich, D-52425, Jülich, Germany
3
High Energy Physics Institute, Tbilisi State University, GE-0186, Tbilisi, Georgia
4
Institute of Nuclear Physics, KZ-050032, Almaty, Kazakhstan
5
L.N. Gumilyov Eurasian National University, KZ-010000, Astana, Kazakhstan
6
St. Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, RU-188350, Gatchina, Russia
7
Institut für Kernphysik, Universität Münster, D-48149, Münster, Germany
8
Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, RU-119991, Moscow, Russia
9
Dubna State University, RU-141980, Dubna, Russia
10
Department of Physics, Moscow State University, RU-119991, Moscow, Russia
11
Physics and Astronomy Department, UCL, WC1E 6BT, London, UK
* e-mail: cyrkov@jinr.ru
Received:
3
May
2018
Accepted:
16
October
2018
Published online:
30
November
2018
The reaction 
was studied at 0.8-2.0 GeV proton beam energies with the ANKE magnetic spectrometer at the COSY synchrotron storage ring. The proton-deuteron pairs emerging with high momenta, 0.6-1.8 GeV/c, were detected at small angles with respect to the proton beam. Distribution over the reaction missing mass 
reveals a local enhancement near the threshold of the pion pair production specific for the so-called ABC effect. The enhancement has a structure of a narrow bump placed above a smooth continuum. The invariant mass of the 
system in this enhancement region exhibits a resonance-like peak at 
GeV/c
2 with the width 
GeV/c
2. A possible interpretation of these features is discussed.
© SIF, Springer-Verlag GmbH Germany, part of Springer Nature, 2018
