Resonance-like coherent production of a pion pair in the reaction \(pd \rightarrow pd \pi\pi\) in the GeV region

The reaction \(p + d \rightarrow p + d + X\) 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 \(d\pi\pi\) system in this enhancement region exhibits a resonance-like peak at \(M_{d\pi\pi}\approx 2.36\) GeV/c2 with the width \(\Gamma \approx 0.10\) GeV/c2. A possible interpretation of these features is discussed.