Reaction γγ→ππ: the (IJPC=00++)-wave spectra at Eγγ(c.m.)∼300–1900 MeV

We calculate the 00++-wave spectra for the reactions γγ→π0π0 and γγ→π+π− on the basis of: (i) the results of the K-matrix analysis of the 00++ amplitudes for the reactions ππ→ππ, KK̄, ηη, ηη′, ππππ, and (ii) recently developed method for calculation of the decay amplitudes f0(13P0qq̄)→γγ, f0(23P0qq̄)→γγ. The reconstructed π0π0 and π+π− spectra can be used as a guide for the extraction of partial widths of scalar/isoscalar resonances f0(980)→γγ, f0(1300)→γγ, f0(1500)→γγ, f0(1750)→γγ. As follows from our calculations, the resonances f0(980) and f0(1500) in the π+π− and π0π0 spectra reveal themselves as dips.