The decay of the dark scalar at a GeV mass scale to the pair of pions

In this talk we consider the pionic decay mode of a hypothetical mediator particle, dark scalar, with mass about 1 GeV. A new estimate for the decay width of such scalar to the pair of pions will be given with use of the gravitational pion form factors that have been obtained earlier from the Belle experimental data. This result will be compared with the well-known answers obtained in ChPT and QCD. In comparison with the estimates derived from dispersion relations in the same mass range, our result shows a non-resonant behavior. The possible effect of this non-resonant answer on the sensitivity curves of future experiments searching for dark scalar will also be discussed. Based on arXiv:2303.12847