Global view of PCAC

When combined with current algebra, the notion of partial conservation of axial currents (PCAC) is quite predictive. In fact, when this PCAC is extended to PCAC consistency for multiple pion or kaon states, the above procedure is in excellent agreement with data for strong, electromagnetic and nonleptonic weak interactions over a wider range of energies even above 1 GeV. Usually physicists are wary of invoking PCAC notions far from the soft-pion limit.