  We compare the virtues of two options for the isospin (I=1 or 2) of the
apparently exotic dibarion resonance d_1^*(1956), as it is noticed by the
DIB2gamma Collaboration (JINR) in the reaction pp -> 2 gamma X below the pion
threshold, and using recent results following from the RMC Collaboration
(TRIUMF) measurement of the relative probability of the double-photon pion
capture in the pi-mesic deuterium atoms.
