References - Bogoliubov Laboratory of Theoretical Physics - JINR

with only modern NN potential are reported. The inclusion 2π-exchange 3NF models
into theoretical calculations removes many of them. In contrast, theoretical calculations
with 3NFs still have difficulties in the reproducing of some spin observables and cross
sections at backward scattering. One of the tools for understanding of the reason of these
disagreements is the investigation of the processes sensitive to the deuteron, 3He( 3H) spin structure and 3-nucleon forces(3NFs). Binary reactions like dd → 3Hp, dd → 3Hen, dp → pd and d3He → p4He are sensitive to the structure of deuteron and 3-nucleon forces.
In addition, the dd → 3Hp( 3Hen) reaction can be used as an effective tool to investigate
the structure 3H and 3He at short distances.
In this report the data on the angular distributions of the vector Ay and tensor Ayy,
Axx, Axz analyzing powers in the −→ dd → 3Hp and −→ dd → 3Hen reactions at 200 and
270 MeV of the deuteron kinetic energy are presented. These data are important for the
preparation of the experiments at the LHEP-JINR Nuclotron-M at higher energies. It is
planned to obtain new experimental data on the polarization observables for the p(d, p)d,
3 4 3 He(d, p) He and d(d, p) H reactions. These data will ensure new information on the spin
structure of light nuclei at the short internucleonic distances.
Experiment on the measurement
of the analyzing powers in the −→ dd →
3 Hp and −→ dd → 3 He n reactions
was performed at RARF(RIKEN,
Japan). The details on the experiment
are described elsewhere [3]. The
experimental results on the vector
and tensor analyzing powers of the
−→ dd → 3 Hp( 3 Hen) reactions are presented
in Fig.1. The errors of the
experimental values include both the
statistical and the systematic errors.
The systematic errors were derived
from the errors of the beam polarizations
measurements. The solid and
long-dashed curves are the results of
ONE calculations [4] using CD-Bonn
and Paris deuteron and 3 He wave
Graph
1
0.5
0
-0.5
Graph
Ay
200 MeV
-1
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
1
0.5
0
-0.5
-1
Graph
1
0.5
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
0
-0.5
-1
Ay
Axz
270 MeV
200 MeV
Paris
CD-Bonn
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
Graph
1
0.5
0
-0.5
-1
Graph
1
0.5
-0.5
Ayy
200 MeV
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
0
-1
Graph
1
0.5
Ayy
270 MeV
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
0
-0.5
-1
Axz
270 MeV
3H
3He
proton
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
Graph
1
0.5
0
-0.5
Graph
-1
0.5
-0.5
Graph
Axx
200 MeV
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
1
0
-1
0.5
-0.5
Axx
270 MeV
0 20 40 60 80 100 120 140 160 180
θ * c.m.s.
1
0
-1
T20
dd->3Hen(0)
dd->3Hp(0)
dd->3Hp(180)
0.1 0.15 0.2 0.25 0.3 0.35 0.4
Ed
GeV
Figure 1: The analyzing powers of the � dd → 3 Hp( 3 He n)
reactions. The solid and long-dashed curves are the results
of ONE calculations.
functions [5],respectively. One can see that ONE calculations are in the qualitative agreement
with the data on the T20. But they don’t reproduce the behavior of the tensor Ayy,
Axx and Axz analyzing powers in the full angular range. The vector analyzing power Ay
equals zero in the ONE model. Some structures in the experimental results on Ay indicate
possibility other than ONE mechanisms in these reactions. The reason of the discrepancy
can be in the non-adequateness of the 3N-bound state spin structure and/or more complicated
reaction mechanism. The multiple scattering calculations are in progress now.
We plan to measure the cross section, vector Ay and tensor Ayy and Axx analyzing
powers in dp-elastic scattering [6] at large angles in c.m.s. in the energy range 0.3-2.0
GeV at Internal Target Station at Nuclotron-M. At deuteron energies below 300 MeV,
Faddeev calculations can provide good description of cross section data, by introducing
a three nucleon force, over the whole angular range. However, their reproduction of the
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