Further Measurements of the Mesotron Lifetime

The average ranges before decay of two monoenergetic mesotron groups have been measured. Within the statistical errors, the ranges are found to be in the same ratio as the average effective momenta, as theoretically predicted. From the two above measurements, and with a mesotron mass $\mu ={10}^8$ ev/${\mathrm{c}}^2$, one obtains the values ${\tau }_0=(2.8\mathrm{}\pm 0.3)\times {10}^{-6\mathrm{}}$ and ${\tau }_0=(2.9\mathrm{}\pm 0.7)\times {10}^{-6\mathrm{}}$ second for the proper lifetime of mesotrons, in excellent agreement with previous measurements by Rossi and Hall.