Alpha-nucleus elastic scattering at intermediate energies

Elastic scattering of 288,340,480 and 699 MeV Alpha-particles was measured on ²⁰⁸Pb, ¹¹⁶Sn and ⁵⁸Ni. The data were analysed in terms of a phenomenological optical model. The optical potentials obtained were found to vary consistently with the target nucleus and the incident energy. The radial zone where the potentials are well determined was studied in detail. The data for ²⁰⁸Pb were also analysed with a folding model. The energy dependence of the strong-absorption radius and of the reaction cross section shows that the nuclear surface becomes slightly transparent for incident energies above 150 MeV per nucleon.     

Deuteron-proton elastic scattering at intermediate energies

The deuteron-proton elastic scattering has been studied in the multiple-scattering expansion formalism. Primary attention has been given to such relativistic problems as a deuteron wave function in a moving frame and transformation of spin states due to Wigner rotation. Parametrization of the nucleon—nucleon t matrix has been used to take the off-energy-shell effects into account. The vector, A _y , and tensor, A _yy , analyzing powers of the deuteron have been calculated at two deuteron kinetic energies: 395 and 1200 MeV. The obtained results are compared with the experimental data. The text was submitted by the authors in English.     

Positron-helium elastic scattering at intermediate energies

Total cross sections for elastic positron-helium collisions have been computed and compared with other theoretical results. Integrated cross sections over small angular regions extending from zero angle, for which a set of experimental estimates is available, are also presented.     

Hadron-nucleon elastic scattering at high energies

A review of experiments on high energy hadron-nucleon elastic scattering is given. Emphasis is placed on the most recent experiments at FNAL and CERN/ISR. Results (mostly preliminary) are discussed and compared with earlier experiments.Presented at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.I like to thank the Czechoslovakian Academy of Sciences and the Organizing Committee of the Symposium, especially Dr. J.Fischer, for their invitation and hospitality. I am indebted to D. D.Jovanovitch of the Michigan-Argonne-Fermilab-Indiana collaboration for sending me their data prior to publication.     

Three-body elastic and inelastic scattering at intermediate energies

The Faddeev equation for three-body scattering at arbitrary energies is formulated in momentum space and directly solved in terms of momentum vectors without employing a partial wave decomposition. For identical bosons this results in a three-dimensional integral equation in five variables, magnitudes of relative momenta and angles. The cross sections for both elastic and breakup processes in the intermediate energy range up to about 1 GeV are calculated based on a Malfliet-Tjon type potential, and the convergence of the multiple scattering series is investigated.     

Calculation of elastic electron-helium scattering at intermediate energies

The two-potential eikonal approximation is applied to the calculation of the differential cross section for elastic scattering of electrons by ground state helium atoms at energies 50 and 100 rV. The results agree very well with experiments.     

Differential cross-section of dp elastic scattering at intermediate energies

The deuteron-proton elastic scattering is studied in the multiple-scattering expansion formalism. The contributions of the one-nucleon exchange, single and double scattering are taken into account. The Love and Franey parameterization of the nucleon-nucleon t -matrix is used, that gives an opportunity to include the off-energy-shell effects into calculations. Differential cross-sections are considered at four energies, T _d = 390 , 500, 880, 1200MeV. The obtained results are compared with the experimental data.     

A search at high energies for antineutrino-electron elastic scattering

We have searched for candidates for the weak neutral leptonic current reaction $\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}{}^{\mathrm{?}}\text{→}\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}{}^{\mathrm{?}}$ in the Fermilab 15 ft bubble chamber filled with a heavy neon-hydrogen mix. Based on zero observed events of this type we find the 90% confidence level upper limit for the rate for this reaction relative to the total antineutrino charged current rate to be 3.9 × 10^?4 and, in the Weinberg-Salam model, sin²θ_W ? 0.37.     

Bounds on the elastic scattering amplitude at finite energies

A bound on the ratio of differential cross sections of particle and antiparticle at finite energies has been derived using the relation between phase and modulus of the scattering amplitude which follows from analyticity, unitarity and crossing symmetry.Presented by Yu. S.Vernov at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.     

Spin effects in elastic pp scattering at high energies

A brief survey is made of those popular and recent models of pp-scattering which incorporate spin at least to some extent. These models are: conventional Regge pole models, models of the eikonal type and geometric (optical) models. Particular attention is paid to the structure of polarization to be expected at higher energies.Presented at the Symposium on Hadron-Hadron Scattering at High Energies, Liblice, Czechoslovakia, June 16–21, 1975.     

Neutron-proton elastic scattering at high energies and small momentum transfers

It is shown that the most recent measurements of differential cross-section at small momentum transfers, integrated and total cross-sections, and the slope of np elastic scattering from 100 to 400 GeV/c are successfully fitted by using the simple Regge pole model proposed by the authors several years ago.     

Proton-proton elastic scattering and nucleon resonance production at high energies

Angular distributions of proton-proton elastic scattering have been measured for incident beam momenta of 10.0, 12.0, 14.2 and 24.0 GeV/c over a range of lab scattering angles from 12 to 152 mrad. This is equivalent to a range of four-momentum transfer squared from about 0.1 to 6.7 GeV² at the highest momentum. Nucleon resonance production in the two-body reaction p + p → p + X has been studied at 24.0 GeV/c incident momentum from 13.5 to 112 mrad by measuring the proton momentum spectra from the elastic peak down to a momentum corresponding to a missing mass of about 2.6 GeV. The new data are compared with previous results and theoretical models.     

Proton-4He elastic scattering at intermediate energies

Differential elastic cross sections and polarizations are calculated in a multiple-scattering formalism for proton-⁴He scattering for energies in the range 0.6–24.0 GeV and for momentum transfers up to 4.0 fm^?1. The calculations include Coulomb and spin effects. Corrections due to target-nucleon overlap and charge exchange are estimated. The results are compared with experimental data.     

Phase shift analysis of heavy-ion elastic scattering measured at intermediate energies

An elastic scattering phase shift analysis based on McIntyre parametrization is presented. It has been applied to¹²C+¹²C system at 360- and 1,016 MeV incident energies as well as to¹⁶O scattering on¹²C,⁴⁰Ca,⁹⁰Zr and²⁰⁸Pb targets at 1,503 MeV. The success of this model allows the interplay between diffraction and refraction to be pinned down: a presence of a nuclear rainbow is clearly evidenced in several cases.     

A precision measurement of pp elastic scattering cross-sections at intermediate energies

We have measured differential cross-sections for elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range . Details of the apparatus and the data analysis are given and the resulting excitation functions and angular distributions presented. The precision of each data point is typically better than 4%, and a relative normalization uncertainty of only 2.5% within an excitation function has been reached. The impact on phase shift analysis as well as upper bounds on possible resonant contributions in lower partial waves are discussed.Received: 24 March 2004, Published online: 19 October 2004PACS: 25.40.Cm Elastic proton scattering - 13.75.Cs Nucleon-nucleon interactions (including antinucleons, deuterons, etc.) - 13.85.Dz Elastic scattering - 21.30.-x Nuclear forces     

Sudden approximation for elastic scattering of composite projectiles at intermediate energies

Elastic scattering of deuterons by nuclei at intermediate energies is investigated by the sudden approximation. Scattering amplitudes of the deuteron are described in terms of those of the constituent nucleons. They consist of the amplitude of nucleon-nucleus single collision and that of double collision. The neglect of the latter explains similarity relations between the deuteron observables and the proton ones, which are found in experimental data. Cross sections and vector analyzing powers calculated with the single-collision terms successfully reproduce the measured ones for ¹⁶O, ⁴⁰Ca and ⁵⁸Ni targets in the energy region, E_d = 200 ˜ 700 MeV. Scattering of ⁶Li by ⁵⁸Ni is investigated in a similar way assuming the d + cluster model for ⁶Li.