11 research outputs found
Separation of Flip and Non-Flip parst of Charge Exchange np->pn at energies Tn = 0.5 - 2.0 GeV
The new Delta-Sigma experimental data on the ratio allowed
separating the Flip and Non-Flip parts of the differential cross section of
charge exchange process at the zero angle by the Dean formula. The
PSA solutions for the elastic scattering are transformed to the
charge exchange representation using unitary transition, and good
agreement is obtain.Comment: 7 pages, 2 figure
Present tectonics of the southeast of Russia as seen from GPS observations
The present tectonics of Northeast Asia has been extensively investigated during the last 12 yr by using GPS techniques. Nevertheless, crustal velocity field of the southeast of Russia near the northeastern boundaries of the hypothesized Amurian microplate has not been defined yet. The GPS data collected between 1997 February and 2009 April at sites of the regional geodynamic network were used to estimate the recent geodynamic activity of this area. The calculated GPS velocities indicate almost internal (between network sites) and external (with respect to the Eurasian tectonic plate) stability of the investigated region. We have not found clear evidences of any notable present-day tectonic activity of the Central Sikhote-Alin Fault as a whole. This fault is the main tectonic unit that determines the geological structure of the investigated region. The obtained results speak in favour of the existence of a few separate blocks and a more sophisticated structure of the proposed Amurian microplate in comparison with an indivisible plate approach
Search for the NN → 6q phase transition in the
The measurements of np-spin observables
at have been performed for the first time
on the Delta-Sigma experimental facility of LHE JINR
up to Pn=4.5 GeV/c using
the monochromatic neutron beam.
They include detailed measurements of the
spin differences
and the study of the elastic
charge-exchange process.
In the
and energy dependencies
over the energy region T–3.7 GeV
the peculiarity at 1.8 GeV was observed.
Such energy behavior was predicted by the QCD approach as a signal of the
phase transition.
For the exhaustive investigation of this effect
it is necessary to measure the energy dependence
of the complete set of np observables
with both longitudinal (L) and transverse (T)
polarizations of the neutron beam and proton target.
This will allow Direct Reconstruction of
all three NN forward Scattering Amplitudes (DRSA) to be performed,
and the observed peculiarity to be checked
around T GeV and at the higher energies
using the Argand diagrams method
Measurements of the ratio R
New experimental results on the ratio Rdp of the quasi-elastic charge-exchange yield at the outgoing proton angle = 0° for the nd
p(nn) reaction to the elastic np
pn charge-exchange yield are presented. The measurements were carried out at the Nuclotron of the Veksler and Baldin Laboratory of High Energies of the JINR (Dubna) at the neutron beam kinetic energies of 0.55, 0.8, 1.0, 1.2, 1.4, 1.8 and 2.0GeV. The intense neutron beam with small momentum spread was produced by break-up of deuterons which were accelerated and extracted to the experimental hall. In both reactions mentioned above the outgoing protons with the momenta p
p approximately equal to the neutron beam momentum p
n, beam were detected in the directions close to the direction of incident neutrons, i.e. in the vicinity of the scattering angle = 0° . Measured in the same data taking runs, the angular distributions of the charge-exchange reaction products were corrected for the well-known instrumental effects and averaged in the vicinity of the incident neutron beam direction. These corrected angular distributions for every of nd
p(nn) and np
pn charge-exchange processes were proportional to the differential cross-sections of the corresponding reactions. The data were accumulated by the Delta-Sigma set-up magnetic spectrometer with two sets of multiwire proportional chambers located upstream and downstream of the momentum analyzing magnet. Inelastic processes were considerably reduced by the additional detectors surrounding the hydrogen and deuterium targets. The time-of-flight system was applied to identify the detected particles. The new Rdp data are compared with the existing ones, which were obtained below 1GeV, and with the calculations which were made using the phenomenological NN amplitude sets