An Isotensor Dibaryon in the $pp\to pp{\pi }^{+}{\pi }^{-}$ Reaction?

Abstract

Exclusive measurements of the quasi-free $pp\to pp{\pi }^{+}{\pi }^{-}$ reaction have been carried out at WASA@COSY by means of $pd$ collisions at $T_p$ = 1.2 GeV. Total and differential cross sections have been extracted covering the energy region $T_p=1.08-1.36$ GeV, which is the region of $N^{\ast }(1440)$ and $\Delta (1232)\Delta (1232)$ resonance excitations. Calculations describing these excitations by $t$-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor $\Delta N$ dibaryon resonance with $I(J^P)=2(1^{+})$ produced associatedly with a pion is able to overcome these deficiencies.

arXiv admin note: substantial text overlap with arXiv:1803.03192