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We have measured pion inelastic scattering from [sup 20]Ne with 180 MeV [pi][sup +] and [pi][sup [minus]] at 12[degree] and from 15[degree] to 90[degree] in 5[degree] steps and with 120 MeV [pi][sup +] from 15[degree] to 90[degree] in 5[degree] steps. We report here on states in the first four [ital K][sup [pi]]=0[sup +] bands, including the 6.73MeV 0[sup +] and the 8.78-MeV [sup 6+] levels. Coupled-channels processes are shown to be important for many states.

Inclusive and exclusive spectra of the {sup 4}He({pi},{pi}{prime},{ital p}) reaction were measured with {pi}{sup +} and {pi}{sup {minus}} at {ital T}{sub {pi}}=140 MeV and {theta}{sub {pi}}=40{degree}, and at 180 MeV and 30{degree}, 40{degree}, 60{degree}, and 80{degree} using the EPICS system at LAMPF in coincidence with elastic plastic scintillators. The inclusive spectra yield cross section ratios {ital R}{sub {pi}}={sigma}({pi}{sup +})/{sigma}({pi}{sup {minus}})=1.1{plus minus}0.1 at both {ital T}{sub {pi}} and all {theta}{sub {pi}}. Exclusive spectra were obtained between {sup 4}He{sup *} excitation energies {ital E}{sub {ital x}}=21.5 and 45.0 MeV. Angular correlation functions for ({pi},{pi}{prime},{ital p}) were extracted at {ital T}{sub {pi}}=180 MeV at the four pion angles for selected regions of {ital E}{sub {ital x}}. The ({pi}{sup +},{pi}{sup +{prime}}{ital p}) angular correlations show a distinct peak near the free proton knockout angle; however, the ({pi}{sup {minus}},{pi}{sup {minus}{prime}}{ital p}) data show either a flat distribution or a mininum near that angle. Calculations, using a distorted wave impulse approximation (DWIA) code which models the ({pi},{pi}{prime}{ital p}) reaction as a pion-induced proton knockout, predict peaks in the angular correlation functions in the quasifree knockout direction and reproduce quite well the ({pi}{sup +},{pi}{sup +{prime}}{ital p}) data above {ital E}{sub {ital x}}=30 MeV. However, these calculations domore » not resemble the ({pi}{sup {minus}},{pi}{sup {minus}{prime}}{ital p}) data at any excitation energy.« less

Exclusive $^{4}\mathrm{He}$(${\mathrm{\ensuremath{\pi}}}^{\ifmmode\pm\else\textpm\fi{}}$,${\mathrm{\ensuremath{\pi}}}^{\ifmmode\pm\else\textpm\fi{}}$'p${)}^{3}$H spectra in the excitation energy range between 21.5 and 44 MeV in $^{4}\mathrm{He}$ were measured at ${\mathit{T}}_{\mathrm{\ensuremath{\pi}}}$=180 MeV at several pion and proton angles. The cross section ratio ${\mathit{R}}_{\mathrm{\ensuremath{\pi}}\mathit{p}}$=\ensuremath{\sigma}(${\mathrm{\ensuremath{\pi}}}^{+}$,${\mathrm{\ensuremath{\pi}}}^{+}$'p)/\ensuremath{\sigma}(${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$,${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$'p) was found to be between 1 and 2 near 22 MeV which is in the region of the ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$=${2}^{\mathrm{\ensuremath{-}}}$, T=0 state. Between 25 and 40 MeV in the continuum, which comprises the giant dipole resonance and broad ${2}^{\mathrm{\ensuremath{-}}}$ and ${2}^{+}$ states, ${\mathit{R}}_{\mathrm{\ensuremath{\pi}}\mathit{p}}$ ranges from 0.22 to 45 in sharp contrast to the predicted values of \ensuremath{\approxeq}1 from a model assuming the entire yield is due to the sequential decay of a state of good isospin, and 6 to 9 from a distorted-wave impulse approximation calculation assuming quasifree proton knockout.

The energy dependence of cross sections for inelastic pion scattering to the /Delta/ = /Delta/ = /Delta/ = 1 transition at 15.11 MeV in /sup 12/C is found to map very closely the /Delta/ = /Delta/ = /Delta/+1 /pi/-nucleon scattering cross sections at beam energies from 50 to 295 MeV. This free /pi/-nucleon energy dependence is due to the prominent /Delta/sub 3/2,3/2/ resonance, corresponding to the first excited nucleon state, which is mirrored in the /pi/-nucleus system with little alteration.

We have observed the broad ${2}^{+}$ member of the ${K}^{\ensuremath{\pi}}$${=0}_{4}^{+}$ band of $^{20}\mathrm{Ne}$ with the $^{20}\mathrm{Ne}$(${\ensuremath{\pi}}^{+}$,${\ensuremath{\pi}}^{+}$') reaction at ${T}_{\ensuremath{\pi}}$=120 and 180 MeV and with $^{20}\mathrm{Ne}$(${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$,${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$') at ${T}_{\ensuremath{\pi}}$=180 MeV. We find an excitation energy of 9.00\ifmmode\pm\else\textpm\fi{}0.18 MeV and a width of 0.8 MeV. The B(E2\ensuremath{\uparrow}) is determined to be approximately 25 to 35 ${e}^{2}$${\mathrm{fm}}^{4}$.

The d(π+, π−)T+++ and the d(π−, π+) T− reactions were studied at an incident pion energy of 260 MeV. Outgoing negative pions were detected at 35° and 55° in the first reaction, and the positive pions at 45° in the second. Indications for structures corresponding to a (π+pp) system with a mass of 2003.0±1.0 MeV and a (π−nn) system with a mass of 200.1±1.5 MeV were observed with marginal statistical significance. Upper limits for the cross sections are obtained.