Search

The vector analyzing power [ital iT][sub 11] and the tensor analyzing power [tau][sub 22]=[ital T][sub 22]+[ital T][sub 20]/ [radical]6 have been measured for [pi][sup +][r arrow][sup 6]L[rvec i] elastic and inelastic scattering (to the 3[sup +]0, 2.19 MeV state) at incident pion energies of 120, 150, 180, and 194 MeV. These data and earlier ones from our group are compared with new coupled channels calculations. Within the coupled channels model, the influence of different nuclear wave functions, the strength of the coupling of the ground and first excited states, and the effects of the phenomenological second-order potential were investigated. It was found that the calculated vector analyzing power [ital iT][sub 11] depends strongly on the transverse form factor whichever nuclear wave function is chosen. In the angular region where the [ital iT][sub 11] data were taken the coupling of the ground to the first excited state has a minor effect on the theoretical predictions. Reasonable agreement with the data can be obtained for a large energy and angular region with the first-order potential only.

The inclusive vector analyzing power [ital iT][sub 11] of [pi][sup +][r arrow][sup 7]Li elastic scattering and inelastic scattering to the 0.47 MeV excited state was measured at several angles for [ital T][sub [pi]]=134, 164, and 194 MeV. The polarization effects were found to be small but nonzero, the trend of the data is well described by a coupled channels calculation. The results of the calculation are more sensitive to variations of the nuclear structure input than to variations of the reaction mechanism.

The vector analyzing power [ital iT][sub 11] of the reaction [pi][ital d][r arrow][ital pp] was measured at [ital T][sub [pi]]=350, 400, and 450 MeV. The results obtained at [ital T][sub [pi]]=350 MeV are in agreement with earlier measurements of [ital iT][sub 11] at 325 MeV. With increasing energies our results show a marked increase in the vector analyzing power up to a value close to its theoretical limit at [ital T][sub [pi]]=450 MeV ([radical][ital s] =2.40 GeV). In this energy region broad structure has been found in earlier measurements of [ital d][sigma]/[ital d][Omega] and [ital A][sub [ital y]0].