Radiative corrections to polarization observables in elastic electron-deuteron scattering in leptonic variables

The model-independent QED radiative corrections to polarization observables in elastic scattering of unpolarized and longitudinally polarized electron beams by a deuteron target are calculated in leptonic variables. The experimental setup when the deuteron target is arbitrarily polarized is considered and the procedure for applying the derived results to the vector or tensor polarization of the recoil deuteron is discussed. The calculation is based on taking all essential Feynman diagrams into account, which results in the form of the Drell-Yan representation for the cross section, and the use of the covariant parameterization of the deuteron polarization state. Numerical estimates of the radiative corrections are given in the case where event selection allows undetected particles (photons and electron-positron pairs) and the restriction on the lost invariant mass is used.     

QED corrections to {\vec A}({\vec e},e'B)X and A({\vec e},e'{\vec B})X reactions: The case of tensor polarization

The model-independent leading radiative corrections to polarization observables in semi-inclusive longitudinally polarized electron-nucleus scattering with the registration of a produced hadron and scattered electron in coincidence were calculated using the Drell-Yan representation in electrodynamics. The cases of a tensor-polarized target or a produced hadron with tensor polarization were considered. The exclusive process of the electrodisintegration of a polarized deuteron was also studied.     

Radiative corrections to deep inelastic electron-deuteron scattering: The case of tensor-polarized deuteron

Model-independent radiative corrections to deep inelastic scattering of an unpolarized electron beam off the tensor-polarized deuteron target are considered. The contribution to the radiative corrections due to the hard photon emission from the elastic electron-deuteron scattering (the so-called elastic radiative tail) is also investigated. The calculation is based on the covariant parametrization of the deuteron quadrupole polarization tensor. Radiative corrections to the polarization observables are estimated numerically for the kinematical conditions of the current experiment at HERA.     

QED corrections in deep-inelastic scattering from tensor-polarized deuteron target

The leading-log model-independent radiative corrections to deep-inelastic scattering of an unpolarized electron beam from the tensor-polarized deuteron target have been considered. The calculation is based on the covariant parameterization of the deuteron quadrupole polarization tensor and the use of the Drell-Yan-like representation in electrodynamics to describe the radiation of real and virtual particles by the initial and scattered electron.     

Reactions p(d, p)d and p(d, p)pn as a tool for studying the short-range internal structure of the deuteron

In recent years, the deuteron structure at short distances has often been treated from the point of view of nonnucleonic degrees of freedom. In this study, measurements of T-odd polarization observables by using a tensorially polarized deuteron beam and a polarized proton target or a proton polarimeter are proposed as a means for seeking quark configurations inside the deuteron.     

Relativistically invariant analysis of -isobar production in deuteron electrodisintegration: : General analysis of polarization effects

The differential cross-section and the polarization observables for Δ-isobar production in the deuteron electrodisintegration process, e^-+d→e^-+Δ+N, are calculated in a general formalism based on structure functions. The obtained expressions have a general nature, hold for one-photon-exchange, assuming P-invariance of the electromagnetic interaction and the conservation of the hadron electromagnetic current. The dependence of the differential cross-section of the e^-+d→e^-+Δ+N reaction on the vector and tensor polarizations of the deuteron target with unpolarized and longitudinally polarized electrons is considered. The general dependence of the asymmetries on two of five kinematic variables, the azimuthal angle φ and (linear polarization of the virtual photon) is calculated. A similar analysis is performed for the polarization of the nucleon produced in γ^*d→ΔN reaction provided the electron beam is unpolarized or longitudinally polarized. Polarization effects, which are due to the strong ΔN-interaction in the final state are calculated. The photoproduction of the Δ-isobar on the deuteron target has been considered in detail, as a particular case. The differential cross-section and various polarization observables have been derived in terms of the reaction amplitudes. The polarization observables due to the linear and circular polarizations of the photon, when the deuteron target is arbitrarily polarized have been derived in terms of the reaction amplitudes. The polarization of the final nucleon is also considered.     

Radiative corrections to polarized inelastic scattering in the coincidence setup

We completely analyze the model-independent leading radiative corrections to the cross section and polarization observables in the semi-inclusive deep-inelastic electron-nucleus scattering with the detection of a proton and the scattered electron in coincidence. The calculations are based on representing the spin-independent and spin-dependent parts of the cross section in terms of the electron structure functions similarly to the Drell-Yan-like representation in electrodynamics. As the applications, we consider the polarization transfer effect from a longitudinally polarized electron beam to the detected proton and the scattering by a polarized target.     

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.     

Theoretical study of deuteron polarization in γ+d → π0+d

The state of polarization of the recoil deuteron in γ+d → π⁰+d on unpolarized and target polarized deuterons is analyzed in detail. A new set of statistical tensors is introduced to describe non-oriented systems, such as the recoil deuteron in γ+d → π⁰+d, and their relationships to the vector and tensor polarization parameters are established. The new statistical tensors reduce, in the case of oriented systems, to Fano's statistical tensors. Numerical results are computed using two different deuteron models for polarized photon asymmetry, polarized target asymmetry and the vector and tensor polarizations of the recoil deuteron, and these are presented at various c.m. pion production angles at different energies in the region of the first π-N resonance. The study of these parameters is suggested as a promising source of information on isoscalar pion photoproduction amplitudes.     

Electroweak radiative effects in the Møller scattering of polarized particles

Physics of Atomic Nuclei - Bremsstrahlung-induced electroweak radiative corrections to observables of the Møller scattering of polarized particles are calculated. The covariant method is used...     

Radiative corrections to observables of <Emphasis Type="Italic">W</Emphasis>-boson production in collisions of polarized hadrons

Ascheme is proposed for studying the nucleon spin with the aid of observables in the production of single W bosons in hadron-hadron collisions. Special attention is given to determining the distributions of polarized quarks in the low-x region. Lowest order electroweak radiative corrections to observables are calculated. For the conditions of future experiments at the RHIC facility, the relevant cross sections and single and double asymmetries are estimated numerically with allowance for radiative corrections.     

Axial observables in d-->p--> breakup and the three-nucleon force

We have measured three axial polarization observables in d-->p--> breakup with a polarized 270 MeV deuteron beam on a polarized proton target. Axial observables are zero by parity conservation in elastic scattering but can be easily observed in the breakup channel at the present energy. Based on a symmetry argument, the sensitivity of these observables to the three-nucleon force might be enhanced. Calculations without three-nucleon force are in fair agreement with our measurement, indicating that the expected sensitivity of axial observables to the three-nucleon force is not confirmed. Including a three-nucleon force in the calculation does not improve the agreement with the data.     

Manifestation of tensor magnetic polarizability of the deuteron in storage ring experiments

It was previously shown that the tensor magnetic polarizability of the deuteron causes the spin rotation with two frequencies and experiences beating for polarized deuteron beams in storage rings. We confirm an existence of this effect and derive general formulae describing deuteron spin dynamics. It is found that an initially tensor polarized deuteron beam can acquire a final horizontal vector polarization of order of 1%. This effect allows to measure the tensor magnetic polarizability of the deuteron in storage ring experiments.     

Variations on the deuteron theme

Several problems concerning the deuteron and having simple analytic solutions are considered. The relation between the electric quadrupole moment of the deuteron and the np scattering amplitude is established. The degree of the circular polarization of the photon emitted in the radiative capture of longitudinally polarized thermal neutrons is found. The anapole, electric dipole, and magnetic quadrupole moments of the deuteron are calculated.     

Polarization transfer in deuteron stripping reactions

Polarization phenomena involving the spins of a and b in the A(a, b)B reaction are discussed using a complete set of irreducible tensors carrying definite spin transfer. The linear model independent equations relating the cross section and the polarization observables with these tensors are shown to be particularly appropriate for the study of spin dependent interactions, preferentially associated with particular values of spin transfer. The DWBA theory of polarization transfer in deuteron stripping reactions is thoroughly discussed and among the 17 polarization observables we distinguish those likely to be more sensitive to spin dependent distortion, to have stronger deuteron D-state effects, to exhibit the sign-rule j-dependence and other forms of j-dependence. For certain deuteron polarizations, when the spin transfer is pure $\text{s =}\text{1}\text{2}$, it is shown that deuteron stripping reactions are transparent to vector polarization transfer and the outgoing nucléon polarization independent of scattering angle and deuteron energy. DWBA calculations including contributions from spin transfer $\text{3}\text{2}$ through the deuteron D-state and spin-orbit distortion show that polarization transfer in such deuteron polarizations can be explored as a method of producing fast polarized neutrons with known polarization.     

Polarization transfer observables in π-d elastic scattering

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.     

Complete calculation of electroweak corrections for polarized Møller scattering at high energies

A complete calculation of electroweak radiative corrections to observables of polarized Møller scattering at high energies was performed. This calculation took explicitly into account contributions caused by hard bremsstrahlung. A FORTRAN code that permitted including radiative corrections to high-energy Møller scattering under arbitrary electron-detection conditions was written. It was shown that the electroweak corrections caused by hard bremsstrahlung were rather strongly dependent on the choice of experimental cuts and changed substantially the polarization asymmetry in the region of high energies and over a broad interval of scattering angles.     

Parity-nonconserving cold neutron-parahydrogen interactions

Three pion-dominated observables of the parity-nonconserving interactions between the cold neutrons and parahydrogen are calculated. The transversely polarized neutron spin rotation, unpolarized neutron longitudinal polarization, and photon asymmetry of the radiative polarized neutron capture are considered. For the numerical evaluation of the observables, the strong interactions are taken into account by the Reid93 potential and the parity-nonconserving interactions by the DDH and EFT models including two different EFT parity-nonconserving two-pion exchange potentials.     

Spin correlation coefficients for neutron-proton radiative capture

We use a theoretical model for deuteron photodisintegration below the pion production threshold, which has previously been used to calculate the observables for which experimental data is available, in order to calculate the spin correlation coefficients for radiative capture of a polarized neutron beam by a polarized proton target. We give results for the coefficients whose measurement is possible in the near future and explain how such experimental results could improve our understanding of the reaction mechanism. We also comment on exciting measurements of the neutron analyzing power at very low energies.