On the π3He3He coupling

A critical discussion of different methods of estimation of the coupling constant f_π³He³He² is given. It is claimed that at present the best way of obtaining information on this coupling constant is to extrapolate certain differential cross sections, in particular, of the elastic ³He³H scattering, to the pion pole. The resulting value f_π³He³He² = 0.055 ± 0.020 is smaller than the corresponding pion-nucleon value. It supports the expected shadowing effects inside the nucleus but disagrees with other more model-dependent estimations.