Pionic X-rays from 12, 13C

The energies and widths of pionic 2p-1s and 3d-2p X-rays have been measured in 12,13C. Values obtained are 12C: 2p-1s E=93.221(55)keV, τ=2077(14)keV3d-2p E=18.400(6)keV, τ=1.17(11)eV13C: 2p-1s E=92.227(27)keV, τ=2.59(11)keV3d-2p E=18.427(5)keV, τ=0.97(10)eV The muonic 2p-1s X-ray energies in 12,13C have also been measured. The strong interaction effects are discussed in relation to recent low-energy pion scattering measurements.