PT Journal
AU Molina, R
   Xie, JJ
   Liang, WH
   Geng, LS
   Oset, E
TI Theoretical interpretation of the D-s(+) -> pi(+)pi(0)eta decay and the nature of a(0)(980)
SO Physics Letters B
JI Phys. Lett. B
PY 2020
BP 135279
EP 4pp
VL 803
DI 10.1016/j.physletb.2020.135279
LA English
AB In a recent paper [I], the BESIII Collaboration reported the so-called first observation of pure W-annihi- lation decays D-s(+) -> a(0)(+) (980)pi(0) and D-s(+) -> a(0)(0)(980)pi(+). The measured absolute branching fractions are, however, puzzlingly larger than those of other measured pure W-annihilation decays by at least one order of magnitude. In addition, the relative phase between the two decay modes is found to be about 0 degrees. In this letter, we show that all these can be easily understood if the a(0)(980) is a dynamically generated state from (K) over barK and pi eta interactions in coupled channels. In such a scenario, the D-s(+) decay proceeds via internal W emission instead of W-annihilation, which has a larger decay rate than W-annihilation. The proposed decay mechanism and the molecular nature of the a(0)(980) also provide a natural explanation to the measured negative interference between the two decay modes.
ER