Structure in the Pion-Proton Total Cross Section between 2 and 7 GeV/c

The total cross sections of ${\pi }^{\pm }$ on protons in the momentum interval 2 to 7 GeV/c have been measured with high precision. The error fluctuations from point to point vary between 10 and 25 μb. Two new pion-nucleon resonances, one in each of the two isotopic states, have been found at the following mass values: $M_{\frac{1}{2}}=2.65\mathrm{}\pm 0.01$ GeV and $M_{\frac{3}{2}}=2.85\mathrm{}\pm 0.01$ GeV. A search for other resonances at higher momenta is discussed.