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The resonance peak observed by WASA@COSY in the total cross section of the reaction of two-pion production in the isoscalar channel of the reaction $pn\to d\pi^0\pi^0$ [1] at invariant mass 2380 MeV with the width of 70 MeV, is considered as one of the most realistic candidate to the dibaryon resonance [2]. The isospin of this resonance is I=0 and spin-parity $J^P=3^+$. A similar resonance structure was observed by ANKE@COSY in the differential cross section of the two-pion production reaction $pd\to pd\pi\pi$ at beam energies 0.8-2.0 GeV with high transferred momentum to the deuteron at small scattering angles of the final proton and deuteron [3]. In this case the kinematic conditions differ considerably from that in Ref. [1] and two final pions were not detected and, therefore, the isoscalar channel was not separated. Nevertheless, in the distribution over the invariant mass $M_{dππ}$ of the final $d\pi\pi$ system of the reaction $pd \to pd\pi\pi$ the resonance peak was also observed at $M_{dππ} ≈ 2.38$ GeV [3]. In order to explain these data, the two-resonance model [5] of the reactionpn → $d\pi^0\pi^0$ was applied in Refs. [4] by inclusion of the t-channel σ-meson exchange between the proton and deuteron in the reaction $pd\to pd\pi\pi$. Recently in Ref. [6] the reaction $\gamma d\to d\pi^0\pi^0$ was studied and an indication to excitation of isoscalar dibaryon resonance $D_{03}(2380)$ and more heavier dibaryons d(2470) and d(2630) was found. These resonances can be excited also in the reaction dd→ dd* at SPD NICA collider. In this work we estimated the differential cross sections of the reactions $pd\to pd\pi\pi$ and $dd \to dd\pi\pi$ assuming excitaion of the $D_{03}(2380)$ dibaryon by σ- meson exchange in t-channel as in Refs. [4] and calculated distributions over the invariant mass of the final $d\pi\pi$ system for these reactions. The extended model [7] for decay channels of the $D_{03}(2380)$ was used in this calculations.
[1] P. Adlarson et al. (WASA@COSY Collab.), Phys. Rev. Lett. 106, 242302 (2011).
[2] H. Clement, Prog. Part. Nucl. Phys. 93 (2017) 195.
[3] V. I. Komarov et al. (ANKE@COSY Collab.), Eur. Phys. J. A (2018) 54: 206.
[4] Yu. Uzikov, N. Tursunbayev, EPJ Web of Conf. 204, 08010 (2019);
N. Tursunbayev, Yu. Uzikov, SciPost Phys. Proc. 3 (2020) 056.
[5] M.N. Platonova, V.I. Kukulin, Phys. Rev. C 87, 025202 (2013).
[6] T.C. Jude et al., Phys. Lett. B 832 (2022) 137277.
[7] M.N. Platonova, V.I. Kukulin, Phys. Rev. D 103 (2021) 11, 114025.
