New decomposition ofππS-wave interaction
The experimental isoscalar �� ! �� S-wave amplitude squared below 1.75 GeV is characterized by a very broad structure f0(4001200) with two narrow dips due to its destructive interference with the f0(980) and f0(1500). The f0(1370) and f0(1710) do not show up clearly in the �� ! �� S-wave amplitude due to their weak coupling to ��. This paper is about the controversial nature of the broad