Role of scalar $$a_0(980)$$ in the single Cabibbo suppressed process $$D^+ \rightarrow \pi ^{+} \pi ^{0} \eta $$

Taking into account that the scalar $$a_0(980)$$ a 0 ( 980 ) can be dynamically generated from the pseudoscalar-pseudoscalar interaction within the chiral unitary approach, we have studied the single Cabibbo suppressed process $$D^+\rightarrow \pi ^+\pi ^0\eta $$ D + → π + π 0 η . We find clear peaks of $$a_0(980)^+$$ a 0 ( 980 ) + and $$a_0(980)^0$$ a 0 ( 980 ) 0 in the $$\pi ^+\eta $$ π + η and $$\pi ^0\eta $$ π 0 η invariant mass distributions, respectively. The predicted Dalitz plots of $$D^+\rightarrow \pi ^+\pi ^0\eta $$ D + → π + π 0 η also manifest the significant signals for $$a_0(980)^+$$ a 0 ( 980 ) + and $$a_0(980)^0$$ a 0 ( 980 ) 0 states. The uncertainties of the results due to the free parameters are also discussed. Our study shows that the process $$D^+\rightarrow \pi ^+\pi ^0\eta $$ D + → π + π 0 η can be used to explore the nature of the scalar $$a_0(980)$$ a 0 ( 980 ) , thus we encourage the experimental physicists to measure this reaction with more precision.

MOMENTUM DISTRIBUTIONS FROM THREE-BODY DECAYING 9Be AND 9B RESONANCES

The complex-rotated hyperspherical adiabatic method is used to study the decay of low-lying 9 Be and 9 B resonances into α, α and n or p. We consider six low-lying resonances of 9 Be (1/2±, 3/2± and 5/2±) and one resonance of 9 B (5/2-) to compare with. The properties of the resonances at large distances are decisive for the momentum distributions of the three decaying fragments. Systematic detailed energy correlations of Dalitz plots are presented.