Resonance-like coherent production of a pion pair in the reaction pd→pdππ in the GeV region

• Published in: The European physical journal. A, Hadrons and nuclei Vol. 54; no. 11
• Main Authors: Komarov, V. I., Tsirkov, D., Azaryan, T., Bagdasarian, Z., Baimurzinova, B., Barsov, S., Dymov, S., Gebel, R., Hartmann, M., Kacharava, A., Khoukaz, A., Kulikov, A., Kunsafina, A., Kurbatov, V., Kurmanaliyev, Zh, Lorentz, B., Macharashvili, G., Mchedlishvili, D., Merzliakov, S., Mikirtytchiants, S., Nioradze, M., Ohm, H., Rathmann, F., Serdyuk, V., Shmakova, V., Ströher, H., Trusov, S., Uzikov, Yu, Valdau, Yu, Wilkin, C.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2018
• Subjects: Hadrons; Heavy Ions; Nuclear Fusion; Nuclear Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Regular Article - Experimental Physics
• ISSN: 1434-6001; 1434-601X
• DOI: 10.1140/epja/i2018-12641-0

. The reaction p + d → p + d + X 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 M x 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 d π π system in this enhancement region exhibits a resonance-like peak at M d π π ≈ 2 . 36 GeV/ c 2 with the width Γ ≈ 0 . 10 GeV/ c 2 . A possible interpretation of these features is discussed.