References - Bogoliubov Laboratory of Theoretical Physics - JINR

DELTA-SIGMA EXPERIMENT - THE RESULTS OBTAINED.
ΔσT (np) MEASUREMENTS PLANNED AT THE NUCLOTRON-M
V.I. Sharov
Joint Institute for Nuclear Research, Veksler and Baldin Laboratory of High Energy Physics,
141980 Dubna, Moscow region, Russia
E-mail: sharov@sunhe.jinr.ru
Abstract
Under the research program of ”Delta-Sigma experiment” project the energy
dependences of the −ΔσL(np) observable and ratio Rdp have been obtained over
the neutron beam energy region of several GeV . Further measurements of the
−ΔσL,T (np) andAookk(np), Aoonn(np) energy dependences using L and T orientations
of beam and target polarizations will be possible in the near future when
both the new high intensity source of polarized deuterons will be put in operation
at the Nuclotron and the T mode of target polarization will be ready. An intensity
of the polarized deuteron beam from new creating polarized deuteron ions source at
the Nuclotron-M will be more then ten times higher then from the existing source
”Polaris”.
1. Introduction. The nucleon beam energy region of 1 − 5 GeV is considered as transitional
one between the usual boson exchange mechanism of NN interaction and nonperturbative
QCD one. So the new experimental NN results to be obtained will promote to
create an adequate phenomenological and theoretical description of NN interaction over
this region. The measurements of the energy behavior of elastic np spin-dependent observables
over this energy region have been proposed [1], successfully started and carried
out at the JINR LHE under the research program of project ”Delta-Sigma experiment”
[2].
The aim of the Delta-Sigma experimental program is to extend investigations of properties
of NN interaction over a new high energy region of free polarized neutron beams.
This neutron beam energy region from 1.2 upto3.7 GeV is provided in the last years
only by the JINR LHE accelerators. The main task of these studies is to determine for
the first time the imaginary and real parts of all the np → np forward (θn,CM =0 ◦ )
and backward (θn,CM = 180 ◦ ) spin dependent np scattering amplitudes over the specified
energy region. To reach this aim a sufficient data set on energy dependences of np spin
dependent observables has to be obtained for direct and unambiguous reconstruction of
these amplitudes.
Under the Delta-Sigma research program [2] the energy dependences of the −ΔσL(np)
observable and ratio Rdp =(dσ/dΩ)(nd)/(dσ/dΩ)(np) have been obtained over the neutron
beam energy region of several GeV . Further measurements of −ΔσL,T (np) and
Aookk(np), Aoonn(np) energy dependences using L and T orientations of beam and target
polarizations will be possible in the near future when both the new high intensity source
of polarized deuterons will be put in operation at the Nuclotron and the T mode of target
polarization will be ready.
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