  The recent discovery of a narrow resonance in D_s+pi^0 by the BABAR
collaboration is consistent with the interpretation of a heavy J^P(0+,1+) spin
multiplet. This system is the parity partner of the groundstate (0-,1-)
multiplet, which we argue is required in the implementation of SU(3)_L x
SU(3)_R chiral symmetry in heavy-light meson systems. The (0+,1+)->(0-,1-)+pi
transition couplings satisfy a Goldberger-Treiman relation, g_pi =
Delta(M)/f_pi, where Delta(M) is the mass gap. The BABAR resonance fits the 0+
state, with a kinematically blocked principal decay mode to D+K. The allowed
D_s+pi, D_s+2pi and electromagnetic transitions are computed from the full
chiral theory and found to be suppressed, consistent with the narrowness of the
state. This state establishes the chiral mass difference for all such
heavy-quark chiral multiplets, and precise predictions exist for the analogous
B_s and strange doubly-heavy baryon states.
