Spin effects in elastic hadron scattering

Spin effects of the high energy elastic nucleon-nucleon scattering in the whole diffraction domain are examined with taking into account the Coulomb-nuclear interference. A new form of the total phase factor of the electromagnetic-hadron interference is obtained for a wide region of transfer momenta up to the diffraction dip domain, and as a result, additional contributions to the analyzing power A _N and double spin correlation parameter A _NN owing to the electromagnetic-hadron interference are determined in the whole diffraction dip domain of high-energy elastic hadron scattering. The energy dependence of these effects is examined including the region of BNL RHIC energies.     

Spin and isospin effects in elastic P-4He scattering near 1 GeV

The coupled-channel method for multiple scattering is employed to describe the p-⁴He elastic-scattering data for a proton laboratory energy of 1.03 GeV. Particular attention is paid to the double spin-flip, double isospin-flip, double spin-isospin flip and to the effects of isobar excitation of the incident proton. It is found that the presently available data is consistent with either the excitation and deexcitation of the proton to an isobar by the ⁴He nucleus or the presence of relatively large double spin-flip nucleon-nucleon amplitudes. The physical difference between these two hypotheses is discussed.     

Spin effects in elastic antiproton nucleus scattering

Elastic scattering of 180 MeV antiprotons by several closed-shell nuclei are analyzed using Glauber's multiple scattering theory. Spin observables in elastic scattering are obtained within this framework. The sensitivity of the polarizations to the spin-flip amplitudes are discussed in terms of the¯NN potential models used for the calculations. Spineffects in angular distribution are found to be small.     

Parity non-conservation in proton-proton elastic scattering

The parity-non-conserving longitudinal asymmetry in proton-proton (p p) elastic scattering is calculated in the lab energy range 0-350 MeV using contemporary, realistic strong-interaction potentials combined with a weak-interaction potential comprised of - and -meson exchanges as exemplified by the DDH model. Values for the - and -meson coupling constants, and , are determined from comparison with the measured asymmetries at 13.6 MeV, 45 MeV, and 221 MeV.Received: 30 September 2002, Published online: 22 October 2003PACS: 21.30.-x Nuclear forces - 24.80. + y Nuclear tests of fundamental interactions and symmetries - 25.40.Cm Elastic proton scattering     

Spin structure of proton-proton scattering in the current-current interaction picture

Using the current-current interaction picture for elastic pp scattering, excellent fits are obtained for all data above 12Gev/c which covers twelve orders of magnitude. It can fit all polarization data, and imply considerable structure in spin-dependent differential cross sections.     

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.     

Spin correlation in pp elastic scattering and in pion production near threshold

An internal polarized gas target in conjunction with a beam of polarized protons stored in the IUCF Cooler storage ring has been used to measure analyzing power and spin correlation parameters between 200 MeV and 450 MeV over a wide range of angles. A consistent absolute beam and target polarization calibration was established by ramping the stored protons up and down in energy. The analyzing power A _y and the spin correlations A _xx , A _yy and A _xz were measured with transverse beam polarization, while determination of A _zz required the development of a longitudinally polarized beam. First experiments on the spin dependence on π₀-production have recently been carried out.     

Spin observables in neutron-proton elastic scattering

The analyzing power, , and the polarization transfer observables , and have been measured in neutron-proton elastic scattering at 260, 318, 386, 472 and 538 MeV for c.m. scattering angles between 64° and 160°. The data were obtained at PSI with a polarized neutron beam and a polarimeter analyzing the transverse polarization of the outgoing proton. They make a significant impact on the knowledge of the Isospin I = 0 nucleon-nucleon scattering. Received: 27 January 1998 / Published online: 30 March 1998     

Beam foil electron spectroscopy near the forward direction

We report measurements of angular distributions of the integrated yields and energy distributions of electrons having velocities near the ion velocity for 0.75, 1 and 2 MeV ³He II incident on amorphous carbon foils of 10, 20 and 50 μg/cm².     

The maximal forward peak in elastic scattering

The maximal sharpness of the forward peak in elastic scattering is constrained by unitarity. This is done by minimizing the average of |t|. The data are within 15% of the maximal sharpness. Our bound and an earlier lower bound on the forward slope constitute a severe restriction on the shape of forward peak.     

π p forward elastic scattering near 1 GeV/c

We have measured the differential cross section of the reaction π⁻p→π⁻p in the range 0.92 ? cos θ_c.m. ? 0.99 at 15 momenta between 0.875 and 1.580 GeV/c. The results we report complete the available data; previous measurements of this reaction do not extend beyond cos θ_c.m.=0.90. We compare our experimental results with dispersion relation predictions. A comparison of our results for B, the slope of the differential cross section, with earlier results shows many discrepancies.     

Further results on small-angle elastic proton-proton scattering at very high energies

This work extends our previous investigations at the CERN Intersecting Storage Rings, with improved statistics at three different energies, wider angular range and a better control over systematic errors. Values for the (diffraction) shape parameter b are given.     

The use of fixed t analyticity in elastic proton-proton scattering

Several methods of exploiting fixed-t analyticity are described and compared with each other. For the forward amplitude the predictions of the real parts from the total cross section data — including the new NAL data — and dispersion relations are found to be in good agreement with the Coulomb interference data. It is also discussed how the results depend on the assumptions on the asymptotic behaviour of the cross section. Furthermore, the conventional dispersion relation approach is compared with the method of analytic parametrization and with the differential operator method. For the non-forward directions, information on the amplitude is extracted from a dispersion relation for the slopes and from a relation between the phase and the modulus of the amplitude.     

High-energy elastic scattering near 90 °

The Euler-Maclaurin summation equation is used to sum the scattering-amplitude series near 90 ° for high energies. With certain plausible assumptions regarding the behavior of the partial amplitudes the cross section for scattering near 90 ° is described by two parameters which also describe the cross section for scattering near 180 °. The calculated results are compared with results found in ⁺p scattering at a momentum of 3 GeV/c.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 12, No. 6, pp. 61–64, June, 1969.     

Sum rules for forward elastic photon scattering

Relations between integrals over forward elastic photon scattering amplitudes, forward elastic cross sections and total cross sections are derived from dispersion relations. A new photon-proton interaction sum rule is derived and evaluated.