Statistics of Pi Mesons

By analyzing the decay of the ${\tau }^{+}$ meson, evidence for the boson character of ${\pi }^{+}$ mesons is obtained which is independent of the Pauli relation between spin and statistics. The usual Dalitz-Fabri expansion in angular momentum eigenfunctions is made, with the important difference that only antisymmetric states are allowed for the two like pions. The matrix elements and ${\pi }^{-}$ distributions are calculated and the latter are compared with the data from 481 ${\tau }^{+}$ decay events by using ${\chi }^2$ to test the statistical significance of each hypothesis about the spin and parity of the final state. If parity is conserved in the decay, then no reasonable fit can be obtained for any spin less than 4. If parity is not conserved, then no reasonable fit can be obtained for any spin less than 3. Thus, if the $\tau$ spin is less than 3, we conclude that ${\pi }^{+}$ mesons obey Bose statistics. This result is independent of any assumption about invariance under time reversal.