On the discrepancy between the FOPT and CIPT approaches for hadronic tau spectral function moments

The discrepancy between the FOPT and CIPT approaches for hadronic \tau τ spectral function moments constitutes major theoretical uncertainty strong coupling determinations from tau decay data. We show can be analytically understood since Borel representations – which have been assumed to identical both previously differ in presence of IR renormalons. This implies that OPE condensate corrections are different may eventually reconciled. In talk we explain difference some mathematical aspects numerical results.