#### Abstract

The inelastic scattering of 162-MeV ${\pi}^{+}$ and ${\pi}^{-}$ by ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ was studied at larger momentum transfer. Several high-spin particle-hole states are observed to be preferentially excited in this reaction. These include the 9.70-MeV (${5}^{-}$,$T=0\mathrm{}$), 11.58-MeV (${6}^{-}$,$T=0\mathrm{}$) and 14.36-MeV (${6}^{-}$,$T=1\mathrm{}$) states. The ratios of the cross sections of the ${6}^{-}$, $T=0\mathrm{}$ state to the ${6}^{-}$, $T=1\mathrm{}$ state are ${1.5}_{-0.2\mathrm{}}^{+0.4\mathrm{}}$ for ${\pi}^{+}$ and 1.7±0.4 for ${\pi}^{-}$, in contrast to ratios of about 4 predicted by simple distorted-wave impulse-approximation calculations.

DOI: http://dx.doi.org/10.1103/PhysRevLett.43.612

- Received 21 June 1979
- Published in the issue dated 27 August 1979

© 1979 The American Physical Society