Decay of Some High-Mass Bosons toπ+π0

We present evidence for three boson structures with masses 1.65, 1.97, and $2.16 \frac{\mathrm{GeV}}{c^2}$ and widths less than $80 \frac{\mathrm{MeV}}{c^2}$ from a study of the reaction ${\pi }^{+}p\to p{\pi }^{+}{\pi }^0$ at $13.1 \frac{\mathrm{GeV}}{c}$. These structures are shown to have $I^G=1^{+}$, therefore excluding even $J$ assignments. This result favors the interpretation of the 1.97 state as a member of the $A_2$ daughter trajectory.