Pion-Nucleon Total Cross Sections from 0.5 to 2.65 GeV/c

Total cross sections of ${\pi }^{+}$ and ${\pi }^{-}$ mesons on protons and deuterons have been measured in a transmission experiment to relative accuracies of ±0.2% over the laboratory momentum range 0.46-2.67 GeV/c. The systematic error is estimated to be about ±0.5% over most of the range, increasing to about ±2% near both ends. Data have been obtained at momentum intervals of 25-50 MeV/c with a momentum resolution of ±0.6%. No new structure is observed in the ${\pi }^{\pm }p$ total cross sections, but results differ in several details from previous experiments. From 1-2 GeV/c, where systematic erros are the smallest, the total cross section of ${\pi }^{-}$ mesons on deuterons is found to be consistently higher than that of ${\pi }^{+}$ mesons by (1.3±0.3)%; about half of this difference may be understood in terms of Coulomb-barrier effects. The $\pi d$ and $\pi N$ total cross sections are used to check the validity of the Glauber theory. Substantial disagreements (up to 2 mb) are observed, and the conclusion is drawn that the Glauber theory is inadequate in this momentum range.