Deuteron structure and diffractive deuteron-nucleus interaction

A nonrelativistic deuteron wave function involving the D-wave state and having a correct asymptotic behavior is constructed on the basis of the experimentally measured deuteron charge form factor G _C(q) and deuteron structure function A(q). The differential cross section for elastic deuteron-nucleus scattering is calculated by using this wave function and is found to agree with experimental data at an energy of 110 MeV. Integrated cross sections for various processes involving deuteron-nucleus interactions are also calculated. The distribution in the emission angle of the center of mass of the neutron-proton system produced in the diffractive dissociation of 110-MeV deuterons in the field of ²⁰⁸Pb nuclei is obtained.     

Quark recombination in deuteron fragmentation

Low-P _T production off deuteron in the fragmentation region is studied on the basis of a six-quark picture of deuteron. It is argued that all the six valence quarks participate equally in the hadronization processes associated with meson and baryon productions. Thex-distribution of the inclusive cross sections is studied in the framework of a quark recombination model. Fit with experimental data leads to a determination of the valence and sea quark distributions in deuteron. Probabilistic arguments applied to a general recombination picture are shown to lead to some experimentally verifiable constraints on baryon multiplicities. Possibilities of determining the various recombination probabilities are also discussed.     

Study of the mechanism of the reaction 2H(π−, π−p)n at relatively high neutron momenta

The ²H(π^?, π^? p)n reaction is experimentally studied at 1 GeV/c for spectator neutron momenta up to 200 MeV/c. The spectator momentum and polar angle distributions and the Treiman-Yang angle distribution are in good agreement with theoretical calculations allowing for the diagrams in which the initial pion rescatters on the nucleons inside the deuteron not more than twice. We conclude that our understanding of the mechanism of the nucleon knock-out from a deuteron is correct. The simple example of the reaction on a deuteron confirms the possibility of describing direct processes with a small number of Feynman diagrams.     

Isoscalar electromagnetic form factors and the structure of the deuteron at high momentum transfer

We derive general expressions for isoscalar electromagnetic form factors of nuclei including meson-exchange processes such as π, ?, ω and ?πγ exchange. Meson-nucleon vertices for nonzero momentum transfer as well as the effect of the finite width of the ?-meson are taken care of. Specifically, the electromagnetic form factors of the deuteron are calculated up to a momentum transfer of q² ≈ 200 fm^?2. A detailed numerical discussion of the various effects on meson-exchange processes is given. The effect of different deuteron wave functions and two types of photon-nucleon form factors are also discussed.     

Contribution of meson-exchange currents to the electromagnetic structure of the deuteron at high momentum transfers

The leading term of the asymptotic expansion of the contributions of the πNN and ρπγ processes to the electromagnetic form factors of the deuteron at high momentum transfers is calculated. The resulting asymptotic behavior is compared with experimental data obtained at the Thomas Jefferson Laboratory. Constraints on the functional dependence of meson-nucleon vertex functions that ensure a correct asymptotic behavior of deuteron form factors are discussed.     

Multiplicity distribution and nuclear effects in π−d interactions at 21 GeV/c

Results on the charged multiplicity distribution in π^?d interactions at 21 GeV/c are presented. The effects due to the two-nucleon structure of the deuteron target are analysed and the contribution of double scattering processes is estimated as a function of charged multiplicity. The evidence against simple cascade models is discussed.     

Low-type equations for coupled pion-2-nucleon and nucleon-nucleon systems

A set of Low-type equations for coupled pion-deuteron and nucleon-nucleon interaction processes is derived by using the standard Lehmann-Symanzik-Zimmermann (LSZ) reduction technique treating a deuteron as 1-particle state. These equations are confronted with the Bethe-Salpeter-type equations obtained previously for the processes under study. An approximate version of Low equation for the pion-deuteron elastic scattering t-matrix is presented and discussed.     

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.     

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.     

Peculiarities of deuteron splitting by the Coulomb field of heavy nuclei

It is shown that the (d, pf) reaction occurs through two channels. The second channel is related to the deuteron splitting in the Coulomb field of the nucleus and the formation of a singlet deuteron with a kinetic energy lower than the incident-deuteron energy by 2.3 MeV, sizes exceeding > a _np, and an isospin equal to 1. The interaction of a singlet deuteron with the initial nucleus leads to occupation of the shape isomer states.     

Intense deuteron beam investigation by activation yield-ratio technique

In this work, the intense deuteron beam from a plasma focus device is investigated by the activation yield-ratio technique. It is shown that boron-carbide (B₄C) and boron-nitride (BN) are complimentary targets for high energy deuteron beam studies. For deuteron spectra of the form dNd/dE∝E−n, when deuteron spectra decrease relatively gradually (n<6) BN is a better choice, while for the case of very rapidly decreasing deuteron spectra (n>6), B₄C is more suitable.     

ΔE-E detector for proton registration in nonmesonic deuteron breakup at the Nuclotron internal target

A design for a ΔE-E detector to investigate deuteron breakup in the Nuclotron-M internal target in a deuteron energy interval of 300–500 MeV is presented. The high-voltage power supply system of the PMT-63, which is based on the computer-controlled Wenzel Electronik module, is briefly described. A light-emitting diode (LED) monitoring system for the ΔE-E detector is considered. The results of testing the ΔE-E detector using cosmic muons and deuteron beams of the Nuclotron are presented.     

Relativistic nuclear corrections to the spin structure function of the deuteron in the light-cone variables

The relativistic deuteron has been considered in the light-cone formalism as a system of two strongly interacting nucleons (two-nucleon approximation). The technique for the calculation of the average helicity of the proton in the deuteron has been considered in the light-cone variables. A receipt has been pro-posed for the consistent calculation of relativistic nuclear corrections to the average helicity of the proton in the deuteron and to the spin structure function of the deuteron g ₁ ^D . Relativistic-correction-induced change in the Bjorken sum rule has been discussed.     

Analysis of large angle p-d elastic scattering: 100–400 MeV

An analysis is presented of large angle proton-deuteron elastic scattering experiments at deuteron energies of 291, 362 and 433 MeV and proton energies of 140 and 316 MeVon the basis of the Kerman-Kisslinger (KK) model (first order). Further analysis is made using the KK model with second order corrections included. The object of the analysis is to determine quantitatively the sensitivity of large angle scattering to the D-state probability (P_D) in the deuteron. It is found that the KK model (first order and also second order corrections included) is not very successful in fitting the data at those energies when used with existing wavefunctions obtained from phenomenological potentials. A value of 6.7% for P_D gives the best fit when the model is used with the modified Moravcsik analytic fit to the Gartenhaus S-state wavefunction (the third approximation). The incoherent contributions of first and second order non-exchange processes are roughly estimated and found to be negligible. An investigation of the ambiguities in the S-state part of the deuteron wavefunction is also presented.     

A study of final state deuteron events in 1.825 GeV/c pd interactions

The study of pd → ndπ⁺ and pd → pdπ^O reactions shows that the “slow deuteron” inelastic events are dominated by peripheral processes. Box diagrams are presented for the production mechanism of the 2.2 GeV/c² dπ enhancements. Evidence is presented that for ‘fast deuteron’ events d¹⁺⁺ and d¹⁺ resonances at 2.375 ± 0.010 GeV/c² with a width of 0.075 ± 0.015 GeV/c² are produced via baryon exchange. The elastic events have been compared with Glauber multiple scattering theory with reasonable agreement.     

The reactiond+d→p+t and elastic deuteron-deuteron scattering at 51.5 Mev

The elastic deuteron-deuteron scattering and the reactionsd(d,p)t andd(d,³He)n have been investigated at an incident deuteron energy of 51.5 MeV. Time-of-flight technique was used for the particle identification. The observed angular distributions for the (d, p) and (d, n) reaction are identical within the accuracy of the experimental data. The experimental results for the reactiond(d, p)t are compared with a theoretical prediction based on the application of a generalized separable potential model to the four nucleon systems. Information on the single deuteron break-up reactiond+d→d+p+n and on the double deuteron break-up reactiond+d→p+p+n+n is contained in the observed continuous proton and deuteron spectra. The double break-up seems to be contribute only with a rather small amount to the whole break-up cross section.     

Spin Physics at ANKE-COSY

The COSY accelerator (Jülich, Germany) provides beams of polarised protons and deuterons. The ANKE facility at COSY is equipped with polarised hydrogen and deuterium atomic gas targets. The reactions investigated with polarised probes at ANKE include the deuteron break-up at small and large momentum transfer, the pion production processes in pp and pn collisions and the near-threshold η meson production in dip $\vec dp \to ^3 He\eta$ process. Use of the polarised deuteron beam properties allowed a precision measurement of the η meson mass. The future experimental program covers the study of the elementary pp and pn-interaction with polarised beams up to the maximal COSY energy, and a double polarised measurement of the A _{x, z} spin correlation parameter in the pN → {pp} _s π process.