M. Bleszynski

Theory of hadron-deuteron elastic scattering in the GeV region

A multiple scattering formalism for the medium energy hadron-deuteron elastic scattering is developed. This approach provides an extension of the Glauber theory incorporating the complete spin structure and the corrections to the eikonal and fixed scatterer approximations. The systematics of the spin observables and their relation to the hadron-deuteron as well as to hadron-nucleon amplitudes are discussed. An approximate cancellation between few corrections to the double scattering term is found which leaves the non-eikonal correction as the dominant one, and often, very important numerically, e.g., in the deuteron tensor polarization. Comparison of the parameter-free predictions of the theory based on the recent NN phase shift amplitudes with the data on polarization observables in pd elastic scattering is made.

Noneikonal effects in spin-dependent proton-nucleus interactions☆

Abstract Simple expressions are derived for the non-eikonal corrections to the Glauber diffraction approximation for the proton-nucleus scattering amplitudes, with the spin dependence of the proton-nucleon amplitudes taken into account. As an example, we study the numerical importance of these corrections for elastic p 58 Ni scattering at 800 MeV.

On the relevance of the Dirac equation to the scattering of medium-energy nucleons from nuclei☆

Abstract The differences between relativistic and nonrelativistic descriptions of medium-energy nucleon—nucleus scattering are discussed. Special attention is paid to a recently developed Dirac optical model in which we point out an ambiguity resulting from the use of an incomplete representation for relativistic nucleon—nucleon scattering amplitude. This ambiguity is reflected in contributions from negative-energy states and in the implementation of the impulse approximation. We also review how a nonrelativistic optical potential can be modified to include relativistic projectile kinematics.

Evidence for the noneikonal effects in the tensor and vector analyzing powers in p-d elastic scattering at 800 MeV☆

Abstract Deuteron tensor and vector analyzing powers have been measured for the first time in p- d elastic scattering at 800 MeV proton laboratory energy for a - t range between 0.032 and 1.038 (GeV/ c ) 2 . The data provide a very sensitive test of the multiple scattering theory at intermediate energies. The inclusion of the noneikonal correction in the Glauber diffraction theory is essential in the description of the data, especially for -t ⪆0.2 (GeV/ c 2 ), where discrepancies of up to 150% are observed with the theory based on the eikonal approximation.

Elastic scattering of 2 GeV polarized deuterons from hydrogen

Abstract Large deuteron vector and tensor asymmetries have been measured for the first time at imtermediate energies. We have used a 2 GeV polarized deuteron beam whose tensor and vector components were 0.75 and 0.25, respectively. The tensor and vector quantities P yy and P yy were extracted from data obtained with the beam polarization normal to the scattering plane, and P xx was obtained when the polarization was precessed into the scattering plane. Analysis of the data using multiple scattering theory demonstrates the considerable sensitivity of the data to the quadrupole form factor of the deuteron and to the double spin flip components of the NN amplitudes.

Proton polarization observables for the elastic and inelastic scattering of 500 MeV protons from 40Ca and 208Pb

Abstract Measurements for the elastic and inelastic scattering of 500 MeV protons from 40 Ca and 208 Pb at small momentum transfers are reported. The induced proton polarization P and the spin rotation parameter Q were measured for the elastic scattering. The spin rotation parameters D SS ′ , D SL ′ , D LL ′ , d LS ′ and the induced polarization P were measured for transitions to the 3 − (3.37 MeV) and 5 − (4.48 MeV) states in 40 Ca and the 3 − (2.61 MeV) state in 208 Pb. Comparisons of the data with the theoretical calculations were carried out in the framework of nonrelativistic and relativistic approaches. We extracted the spin-up and spin-down channels for the elastic scattering cross sections and found that predictions of the relativistic and nonrelativistic approaches agree well with the spin-up channel data and differ considerably in the spin-down channel.

Some proton spin observables obtained in p-d elastic scattering at 500 and 800 MeV

Abstract Measurements of the spin transfer observables D NN , D SS , and D LS in p + d → p + d at 500 and 800 MeV are reported. In addition we have measured the polarization, P , and the asymmetry A y . The data were taken in the range 0.2 t c ) 2 . Comparison of the observables is made with the predictions of a relativistic multiple scattering model employing the results of a recent phase shift analysis of NN scattering data.

Spin observables in proton deuteron elastic scattering

Some interesting aspects of spin observables in medium energy proton‐deuteron scattering are discussed. It is argued that measurements of spin observables in this reaction can provide new information on the three‐body (contact) interactions. Such an information is not available from measurements of NN observables and can be obtained from the analysis of the 12 amplitudes which describe p‐d elastic scattering. We discuss the sensitivity of the spin observables to such three‐body interactions in the framework of a realistic model in which each of these amplitudes is separated into 1) ‘‘trivial part,’’ involving single and double scattering terms, unambiguously expressible in terms of physical nucleon‐nucleon (NN) scattering amplitudes and 2) the ‘‘nontrivial part’’ which can not be expressed in terms of two‐body interactions, and represents contributions generated by three‐body forces. We find that the agreement between the data and the model predictions is considerably improved when such three‐nucleon inte...

Proton-deuteron elastic scattering at medium energy and relativistic models of multiple scattering☆

Abstract We have constructed a simple model of proton-deutron elastic scattering which can incorporate either a two-dimensional Pauli matrix or four-dimensional Dirac matrix parametrization of the nucleon-nucleon scattering amplitude. The model includes the S-and D-wave components of the deuteron wave function but neglects interactions with the spins of the target nucleons and is intended to provide an estimate of the magnitude of the differences between relativistic and non-relativistic treatments. We find these differences to be quite large and attribute them primarily to the intermediate negative energy states which are present only in the relativistic calculation.

Elastic pp scattering at 1.463 GeV/c in the Coulomb interference region☆

Abstract The differential cross section for elastic pp scattering has been measured at 800 MeV, for laboratory angles ranging between 1.2° and 4.3° (lab). The ratio ϱ of the real to imaginary parts of the forward spin-independent scattering amplitude and the combined magnitudes of the forward double spin-flip amplitudes have been extracted from the data and are compared with the results of recent forward dispersion relation calculations and phase shift analyses.