  The fragmentation of deuterons into pions emitted forward in the kinematic
region forbidden for free nucleon-nucleon collisions is analyzed. It is shown
that the inclusion of the non-nucleonic degrees of freedom in a deuteron
results in a satisfactory description of the data for the inclusive pion
spectrum and improves the description of the data about $T_{20}$. According to
the data, $T_{20}$ has very small positive values, less than 0.2, which
contradicts the theoretical calculations ignoring these degrees of freedom.
