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Polarization transfer measurements in π+ elastic scattering have been performed at two incident pion energies, one below and one at the Δ(3, 3)-resonance. Using a vector polarized deuteron target four polarization transfer observables are determined. The results are compared to predictions from Faddeev calculations.

Polarization transfer observables in π + d elastic scattering have been measured for the first time. Four polarization transfer parameters were determined at pion energies T π =134 MeV and 180 MeV at scattering angles θ π ,C.M. between 100° and 140° using a deuteron target polarized perpendicular to the scattering plane and a deuteron tensor polarimeter. The data are compared to different predictions from the SAID phase shift analysis and Faddeev calculations.

Polarization transfer measurements in π+ elastic scattering have been performed at two incident pion energies, one below and one at the Δ(3, 3)-resonance. Using a vector polarized deuteron target four polarization transfer observables are determined. The results are compared to predictions from Faddeev calculations.

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].

New experimental results are presented on the interaction of pions with nuclei of mass A = 2,3,4 and 6. The data are compared with theoretical calculations. Some open theoretical problems are discussed and an outlook on future experiments is given.

The vector analyzing power {ital iT}{sub 11} was measured for {pi}{sup +}-{sup 6}{rvec L}i elastic and inelastic scattering (3{sup +}, 2.19 MeV) at 100, 134, 164, and 219 MeV, in an angular range between 40{degree} and 125{degree} using a vector polarized {sup 6}LiD target. Sizable spin effects were observed over most of the angular range. The data were compared with a number of theoretical predictions based on different scattering models and nuclear structure input. None of the calculations is able to reproduce the data set; however, it appears that the vector analyzing power {ital iT}{sub 11} is mostly sensitive to the nuclear wave function chosen. The angular distribution of {ital iT}{sub 11} in {pi}{sup +}-{sup 6}Li elastic and inelastic scattering is discussed in terms of nuclear form factors and elementary {pi}{ital N} amplitudes.

The vector analyzing power {ital iT}{sub 11} has been measured for the first time for {pi}{sup +}{ital d} and {pi}{sup {minus}}{ital d} elastic scattering at {ital T}{sub {pi}}=180 MeV in the angular range between 50{degree} and 110{degree}, using a polarized deuteron target and a magnetic spectrometer. The data are compared with theoretical calculations involving different Coulomb prescriptions.

The analyzing power ${\mathit{A}}_{\mathit{y}}$ was measured for ${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{-}}}^{15}$N\ensuremath{\rightarrow} elastic scattering at ${\mathit{T}}_{\mathrm{\ensuremath{\pi}}}$=164 MeV between 40\ifmmode^\circ\else\textdegree\fi{} and 100\ifmmode^\circ\else\textdegree\fi{} using a polarized $^{15}\mathrm{NH}_{3}$ target. Within the statistical accuracy of the data ${\mathit{A}}_{\mathit{y}}$(\ensuremath{\theta}) was found to be zero over the full angular range. These data together with differential cross sections from the literature are compared with theoretical predictions based on a momentum-space coupled-channel formalism. While the cross section is very well reproduced there are large discrepancies in the analyzing power for which large spin effects are predicted close to the cross-section minima. Possible deficiencies in the theoretical model are discussed.

The triple differential cross section {ital d}{sup 3}{sigma}/{ital d}{Omega}{sub {ital p}}{sub 1}{ital d}{Omega}{sub {ital p}}{sub 2}{ital d}{sub p}{ital p}{sub 1} was measured for the {pi}{sup +}{ital d}{r arrow}{pi}{sup 0}{ital pp} reaction as a function of proton momentum, in a kinematically complete experiment at {ital T}{sub {pi}}=228 and 294 MeV. The two outgoing protons were detected in coincidence with plastic scintillator detectors, and their momenta determined by time-of-flight, at several angle pairs in regions of phase space far away from quasifree kinematics. The data are compared with predictions from the relativistic Faddeev calculation of Garcilazo.

Vector and tensor analyzing powers were measured for π+‐6Li↘ and π+‐7Li↘scattering in the angular range between 50° and 110° at several pion energies in the region of the Δ(3,3) resonance. The data are compared to predictions from a coupled channel model. Within this model the sensitivity to variations of the nuclear structure input and the reaction mechanism are investigated.

The first measurements of pion scattering and pion single charge exchange on polarized complex nuclei, obtained at PSI, LAMPF and TRIUMF, are reported. Large spin effects were obtained in pion elastic and inelastic scattering (3+, 2.19 MeV state) in \({}^{6}\overrightarrow{\text{Li}}\). Contrary to these results only small analyzing powers were obtained for pion elastic scattering from \({}^{13}\overrightarrow{\text{C}}\) and \({}^{15}\overrightarrow{\text{N}}\). However, in pion single charge exchange on \({}^{13}\overrightarrow{\text{C}}\) large spin effects were seen. The data are compared with theoretical predictions applying the momentum space optical model and the ∆-hole model, as well as DWIA. In general, the agreement is quite poor, and there are indications that the scattering models as well as the nuclear structure input must be refined.

New experimental results are presented on the major πd reaction channels, i.e. elastic scattering, breakup, charge exchange and absorption. The data are compared to recent calculations based on relativistic Faddeev theory. Some open theoretical problems are discussed and an outlook on future experiments is given.

The angular distributions of the analyzing power Ay and of the differential cross section d σ/ d Ω in p p elastic scattering have been measured at 439 and 544 MeV/c. The results of Ay are compared with various theoretical models.

We report here on the experiment PS198 at LEAR which was completed in June 1988. The aim of that experiment was the measurement of spin observables in p − p and p − d elastic scattering in order to study the N − N interaction in the two isospin states I = 1 and I=0. It was foreseen to measure the full angular distribution of the differential cross section and of the analyzing power in p − p elastic scattering at few incident momenta between 450 and 750 MeV/c.

The vector analyzing power iT/sub 11/ has been measured for the ..pi..d breakup reaction in a kinematically complete experiment. The dependence of iT/sub 11/ on the momentum of the proton has been obtained for 36 pion-proton angle pairs at T/sub ..pi../ = 134 and 228 MeV. The data are compared with predictions from the new relativistic Faddeev theory of Garcilazo. The sensitivity of the observable iT/sub 11/, in particular in the np final-state interaction region, to details of the theory is investigated.

The vector analyzing power iT/sub 11/ has been measured in the ..pi..d..-->..2p reaction using a vector polarized deuteron target. The data consist of an angular distribution of iT/sub 11/ at T/sub ..pi../ = 256 MeV, and a four point excitation function of iT/sub 11/ taken at a center of mass angle of 55/sup 0/. The angular distribution has been fit with associated Legendre polynomials.

The composite spin observable tau/sub 22/equivalent(T/sub 22/+T/sub 20// ..sqrt..6 ) has been measured at five incident pion energies between 134 and 294 MeV, in an angular range between 90/sup 0/ and 170/sup 0/, using a tensor-polarized deuterium target. New, accurate data for the vector analyzing power iT/sub 11/ were obtained at the same time. In combination with the results reported in part I of this series, our measurements allow us to determine the three analyzing powers T/sub 20/, T/sub 21/, and T/sub 22/, separately, and compare them with existing theoretical calculations, all of which fail, in one way or another, to reproduce the entire data set.

We have measured energies and angular distributions of three protons detected in coincidence following absorption of 228 MeV ${\ensuremath{\pi}}^{+}$ in carbon. The counters used were arranged in a geometry that should have enabled observation of the two-step process of proton knockout followed by quasi-deuteron absorption of the recoil pion. The absence of high energy protons emitted in the backward direction provides strong evidence that such a two-step process does not contribute appreciably to the total absorption cross section, and suggests that in fact the pion may scatter several times before finally being absorbed on a quasi-deuteron.

We present the first measurements of spin effects in {pi}{sup +} elastic and inelastic scattering from complex nuclei, {sup 15}{rvec N}({1/2}{sup {minus}}) and {sup 6}L{rvec i}(1{sup +}). For the case of {sup 15}{rvec N}, the analyzing power {ital A}{sub {ital y}} was measured at {ital T}{sub {pi}}=164 MeV between 60{degree} and 100{degree}. Although large values of {ital A}{sub {ital y}} are predicted by theory, the data are consistent with zero. For the case of {sup 6}L{rvec i}, the analyzing power {ital iT}{sub 11} was measured at {ital T}{sub {pi}}=134 and 164 MeV, between 50{degree} and 110{degree}. Large values of {ital iT}{sub 11} were found at some angles, but the measured angular distributions differ considerably from theoretical predictions.

Three-fold differential cross sections \ensuremath{\sigma}(${\mathrm{theta}}_{\ensuremath{\pi}}$,${\mathrm{theta}}_{\mathrm{p}}$,${P}_{\mathrm{p}}$) have been measured in a kinematically complete experiment over a large region of phase space at 228 and 294 MeV incident pion energy. The data are compared with predictions from a relativistic Faddeev calculation. Excellent agreement is found over most of the phase space. From this good agreement between theory and experiment there appears to be no need for the inclusion of nonconventional dynamics, such as the excitation of dibaryon resonances.

At E d = 52 MeV the angular distribution of the outgoing protons in the reaction 14 N(d, p o ) 15 N has been measured. The data are compared to those at E d = 12 and 31 MeV and to (d, d) and (p, p) experiments at almost the same energy. Calculations with the standard DWBA and the impulse approximation are performed. The results support the notion that the latter might provide a more adequate description at high energies.

Inelastic scattering of π+ and π− exhibits strongly excited giant resonance structures. Besides the giant quadrupole resonance centered around 14 MeV, structures are observed at 16.8 MeV which can be fitted with a mixing of L=0 and L=1, and around 25 MeV (E x = 110A − 1 3 ) .

The vector analyzing power (iT/sub 11/) in elastic ..pi..-d/sub pol/ scattering has been measured for several angles at T/sub ..pi../=142 and 256 MeV. The results are compared with calculations reported in the literature. At the lower energies, Faddeev calculations agree fairly well with the data. At the higher energies, the experimental results differ markedly from any conventional calculation, but agree surprisingly well with predictions in which effects of dibaryon resonances are explicitly included.

The 12 C (π,π′γ) 12 C ∗ (2 + , T=0,4.44 MeV ) angular correlation function was measured at Tπ=162MeV. Da taken in the reaction plane for a range of γ-angles at each of two pion angles support recent theoritical predictions using the isobar-hole formalism.

Full angular distributions of the differential cross-section dσ/dμ and of the analysing power Ay in p p elastic scattering have been measured at 697 MeV/c. The results of Ay are compared with the predictions of various theoretical models.

The vector analysing power, iT11, and differential cross section for the π + d →π + pn reaction at Tπ = 228 MeV were measured in a kinematically complete experiment, using a polarized deuteron target. Results are presented for a pion angle of 85° with six proton angles between 27° and 61°. A comparison is made with theoretical calculations.

The vector analyzing power (iT/sub 11/) in elastic ..pi..-d scattering has been measured for several angles at T/sub ..pi../ = 219, 256, 275, and 294 MeV. Strong oscillations are confirmed at 256 MeV. The data are compared with Faddeev calculations; Faddeev amplitudes plus the /sup 3/F/sub 3/(2220) dibaryon resonance only; and Faddeev amplitudes plus the /sup 1/G/sub 4/(2430) dibaryon resonance only. At 219 MeV the Faddeev calculations are consistant with the data, while at the higher energies the general trend of the data favors the admixing of the /sup 1/G/sub 4/ dibaryon resonance. The forward angle data at 294 MeV are not well described by an existing calculation.

Inelastic pion scattering from $^{16}\mathrm{O}$ has been studied by measuring the spectrum of pions down to 40 MeV at five angles between 30\ifmmode^\circ\else\textdegree\fi{} and 134\ifmmode^\circ\else\textdegree\fi{} for three incident pion energies: 114, 163, and 240 MeV. The spectra are dominated by a broad peak due to quasielastic scattering from a single nucleon in the nucleus. The systematics of the spectra are discussed with emphasis on the pion-nucleus interaction dynamics including the effect of absorption. The partial ${\ensuremath{\pi}}^{+}$-$^{16}\mathrm{O}$ cross sections for all nonradiative channels are estimated.NUCLEAR REACTIONS $^{16}\mathrm{O}(\ensuremath{\pi}, {\ensuremath{\pi}}^{\ensuremath{'}})$ $E=114, 163, 240$ MeV. $\ensuremath{\theta}=30\ensuremath{-}134\ifmmode^\circ\else\textdegree\fi{}$, full inelastic spectrum measured; $\ensuremath{\sigma}(\ensuremath{\theta})$. Discussion of nuclear medium effects on quasifree processes, $\ensuremath{\Delta}$ propagation.

The elastic and inelastic scattering of 180 MeV positive and negative pions from 26 Mg has been measured. From these data the ratios of neutron and proton nuclear transition matrix elements have been determined for the first and second excited states. These ratios are compared with those obtained from electromagnetic transitions in mirror nuclei and with shell model predictions.

The dynamics of the ΔN-system in the lightest nuclei, its effects, and properties are reviewed and discussed.

The vector analyzing power iT/sub 11/ has been measured for the ..pi..d elastic scattering reaction at 12 incident pion energies between 117 and 325 MeV, using a vector polarized deuteron target. The results cover an average of 14 angles per incident pion energy. A detailed comparison with existing Faddeev calculations is made. The effect of including dibaryon resonances with one of these predictions is investigated.

We have measured the reactions 12 C (π ± , π ± d ) 10 B and 12 C (π ± , π ± t ) 9 B at an incident pion energy of 180 MeV, with two spectrometers in coincidence. The ratio σ(π+, π+d)/σ(π−, π−d) agrees with the iso-spin prediction of unity. There is evidence for quasi-elastic πd acattering. We obtain the surpising result that the ratio σ(π, πd)/σ(π, πp), for excitation energies less than 10 MeV, is equal to the ratio (dσ/dω) (πd)/(dσ/dω) (πp) for elastic (πd) and (πp) scattering at all the points we have measured. The ratio σ(π−, π−t)/gs(π+, π+t) is approximately one and there is no evidence for quasi-elastic πt scattering.

The vector analyzing power iT/sub 11/ has been measured for the ..pi..d..-->..2p reaction at seven incident pion energies between 112 and 325 MeV, using a vector polarized deuteron target. The results cover an average of 12 angles per incident pion energy. A comparison with existing theoretical calculations is made. The value of these data with respect to ongoing phase shift analyses of the pp..--> pi..d reaction is discussed.

There has been remarkable experimental and theoretical progress in the field ofπd interactions in the last few years. Within the uncertainties of the theory the experimental data in theπd breakup and theπd elastic scattering reaction can be fairly well reproduced. Theoretical problems remain in the absorption channel, but there is a hope that with a few additional measurements of tensor polarization and spin transfer observables in this reaction a partial wave amplitude analysis may localize the theoretical difficulties. In addition it is very important to provide data on the deuteron tensor polarizations and the spin transfer parameters for theπd elastic scattering reaction in order to obtain a reliable set of phase shifts, which may reveal resonance structures in this reaction channel.

The composite spin observable ${\ensuremath{\tau}}_{22}$\ensuremath{\equiv}(${T}_{22}$+${T}_{20}$/ \ensuremath{\surd}6 ) has been measured at five incident pion energies between 134 and 294 MeV, in an angular range between 90\ifmmode^\circ\else\textdegree\fi{} and 170\ifmmode^\circ\else\textdegree\fi{}, using a tensor-polarized deuterium target. New, accurate data for the vector analyzing power ${\mathrm{iT}}_{11}$ were obtained at the same time. In combination with the results reported in part I of this series, our measurements allow us to determine the three analyzing powers ${T}_{20}$, ${T}_{21}$, and ${T}_{22}$, separately, and compare them with existing theoretical calculations, all of which fail, in one way or another, to reproduce the entire data set.

The elastic and inelastic (3 − , 2.6 MeV) scattering of pions by 208 Pb has been measured at 80 MeV ( π + only) and 116 MeV (π + and π − ). An optical potential model including quadratic density terms reproduces well the transition from diffractive scattering at the higher energies to the non-diffractive behavior observed at 50 MeV. Good agreement with the inelastic data is obtained with a collective model using the same deformation length βR = 0.85 fm ( β = 0.13) for π + and π − .

Study of the elastic scattering of 600-MeV protons from light nuclei. Differential cross sections have been obtained for the scattering of protons from hydrogen, deuterium, helium-3, and helium-4. Polarization was measured for deuterium and He-4 nuclei. The p-p cross-section data are in excellent agreement with the predictions from the Livermore phase shifts. Small-angle p-D, p-He-3 elastic scattering data are compared with calculations based on the multiple-scattering theories of Watson and Glauber.

Proton-deuteron elastic large angle scattering cross sections, noting backward peak consistent with baryon exchange mechanism with resonance transfer

The differential cross section for elastic scattering of 600-MeV protons from $^{4}\mathrm{He}$ has been measured for laboratory angles between 4\ifmmode^\circ\else\textdegree\fi{} and 44\ifmmode^\circ\else\textdegree\fi{}. The data are analyzed in terms of the diffraction approximation of Glauber.

Cross sections measured for symmetric /p, 2p/ reactions on deuterium and He, discussing nonsymmetric /p, 2p/ events in He