Speaker
Description
At present as one of the most realistic candidate to dibaryon resonance is considered the resonance $D_{IJ}=D_{03}$ observed by WASA@COSY \cite{WASA11} in the total cross section of the reaction of two-pion production $pn\to d\pi^0\pi^0$, here $I$ is the isospin and $J$ is the total angular momentum of this resonance. Very 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 \cite{Cyrkov}. In the distribution over the invariant mass $M_{d\pi\pi}$ of the final $d\pi\pi$ system the resonance peaks were observed at $M_{d\pi\pi}\approx 2.38$~GeV \cite{Cyrkov} that is the mass of the isoscalar two-baryon resonance $D_{IJ}=D_{03}$, while the kinematic conditions differ considerably from that in Ref. \cite{WASA11}. This data we analyzed in Ref.\cite{UzikovTurs} assuming excitation of the $D_{03}$ resonance via t-channel $\sigma$-meson exchange between the proton and deuteron and using the two-resonance mechanism of the $D_{03}$ resonance decay \cite{PK2013}. The shapes of the distributions over the invariant masses of the final $d\pi\pi$ and $\pi\pi$ systems were explained qualitatively in \cite{UzikovTurs} assuming the lowest values of the orbital angular momenta in the vertices $\sigma d\to D_{03}$ ($L=2$), $D_{03}\to D_{12}+\pi$ ($l_1=1$), $D_{12}\to d+\pi$ ($l_2=1$). In this work we study the role of higher orbital momenta in those vertices ($L=2,4,~l_1=1,3,5,~l_2=1,3$). Furthermore, a contribution of the $D_{03}$ excitation to the $pd$-backward elastic scattering is studied in the 1 GeV region.
\bibitem{WASA11} P.~Adlarson {\it et al.}, (WASA@COSY Collab.), Phys. Rev. Lett. {\bfseries 106}, 242302 (2011).
\bibitem{Cyrkov} V.~Komarov et al. (ANKE@COSY Collab.) Eur. Phys. J. {\bfseries 54}, 206 (2018).
\bibitem{UzikovTurs} Yu.~Uzikov, N.~Tursunbayev, EPJ Web Conf. {\bfseries 204}, 08010 (2019).
\bibitem{PK2013} M.N.~Platonova, V.I.~Kukulin, Phys. Rev. C {\bf 87}, 025202 (2013).
