scholarly journals The possibility of studying polarization observables in reactions of the production of pions by polarized beams of protons and deuterons at the JINR LHEP

2019 ◽  
Vol 204 ◽  
pp. 05004
Author(s):  
Anatoliy Litvinenko
Keyword(s):  
Experimental Data ◽  
Hadronic Matter ◽  
Accelerator Complex ◽  
Polarized Beams ◽  
Polarized Deuterons ◽  
Baryon Charge ◽  
Polarized Protons ◽  
Polarization Observables

Along with studying the properties of strongly excited hadronic matter at high densities of the baryon charge, studies with polarized protons and deuterons are planned at the LHEP accelerator complex (see [1–3]). The purpose of this note is to analyze the possibility of obtaining new experimental data, based on the presence of beams of polarized protons and deuterons. In addition, the use of extracted beams of tensor-polarized deuterons to study the structure of the deuteron at small internucleon distances is discussed.

scholarly journals DETERMINATION OF E AND G OBSERVABLES IN η PHOTOPRODUCTION ON THE CLAS FROZEN SPIN TARGET (FROST)

2014 ◽  
Vol 26 ◽  
pp. 1460115
Author(s):  
◽  
IGOR SENDEROVICH ◽  
B. T. MORRISON ◽  
M. DUGGER ◽  
B. RITCHIE ◽  
...  
Keyword(s):  
Baryon Spectrum ◽  
Preliminary Results ◽  
Extensive Data ◽  
Polarized Protons ◽  
The World ◽  
Double Polarization ◽  
Linearly Polarized ◽  
Beam Incident ◽  
Polarization Observables

Polarization observables are vital for disentangling overlapping resonances in the baryon spectrum. Extensive data have been collected at Jefferson Lab in Hall B with circularly and linearly polarized tagged photon beam incident on longitudinally polarized protons provided by the Frozen Spin Target (FROST). The focus of the described work is on η photoproduction, which acts as an "isospin filter", isolating the N*(I = 1/2) resonances. Preliminary results for the double-polarization observables E and G are presented. There are currently no data on these in the world database for η photoproduction.

scholarly journals NICA Facility in Polarized Proton and Deuteron Mode

2016 ◽  
Vol 40 ◽  
pp. 1660096
Author(s):  
A. D. Kovalenko ◽  
A. V. Butenko ◽  
V. D. Kekelidze ◽  
V. A. Mikhaylov ◽  
A. M. Kondratenko ◽  
...  
Keyword(s):  
Weak Field ◽  
Beam Momentum ◽  
Fixed Target ◽  
Momentum Range ◽  
Polarized Beams ◽  
Polarization Control ◽  
Polarized Protons ◽  
Polarized Proton ◽  
Nica Project ◽  
And Control

NICA project at JINR is aimed at the experiments with polarized protons and deuterons at both as fixed target and colliding mode over beam momentum range from 2 to 13.5[Formula: see text]GeV/c. Polarized beams are injected into collider from the Nuclotron-superconducting synchrotron. Dynamic solenoid “Siberian snakes” are proposed to prevent resonance depolarization of proton beam during acceleration in the Nuclotron up to momentum of 6 GeV/c and further in the collider up to the maximum momentum after storage and stochastic cooling of necessary number of particles in each ring. By means of pair of the Snakes placed in the opposite collider straight sections “spin transparency” mode is provided. Stabilization and control of the polarization is reached due to “weak field” solenoids integrated in the lattice. The proposed scheme of the polarization control is universal and can be used for different ion spices (p, d, t, He3…).

scholarly journals Born Approximation for Polarization Observables at the Scattering of Protons by 40Ca Nuclei

2020 ◽  
Vol 65 (5) ◽  
pp. 369
Author(s):  
O. V. Babak ◽  
Yu. A. Berezhnoy ◽  
V. P. Mikhailyuk
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Born Approximation ◽  
Reasonable Agreement ◽  
Optical Model ◽  
Proton Scattering ◽  
Elastic Proton ◽  
Nucleus Scattering ◽  
Polarization Observables ◽  
Analytical Expressions

A development of the optical model for the description of the hadron-nucleus scattering is proposed. When describing the behavior of polarization observables for the elastic proton scattering on 40Ca nuclei in the energy interval from 200 to 800 MeV, the Born approximation is used. Analytical expressions for the scattering amplitudes, as well as for the differential cross-sections and polarization observables, are obtained. The comparison of the scattering observables calculated in the 1st and 2nd Born approximations is made. It is shown that the observables calculated in this approach are in a reasonable agreement with the available experimental data.

scholarly journals Study of soft photon yield in pp and AA interactions at JINR

2020 ◽  
Vol 235 ◽  
pp. 03003 ◽  
Author(s):  
Elena Kokoulina ◽  
Nurlan Barlykov ◽  
Vladimir Dudin ◽  
Vladimir Dunin ◽  
Andrey Kutov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electromagnetic Calorimeter ◽  
Gadolinium Gallium Garnet ◽  
Accelerator Complex ◽  
Photon Yield ◽  
Comprehensive Understanding ◽  
World Data ◽  
The World ◽  
Low Threshold ◽  
Superconducting Accelerator

Over 30 years there has been no comprehensive understanding of the mechanism of soft photons (energy smaller than 50 MeV) formation. Experimental data indicate an excess of their yield in hadron and nuclear interactions in comparison with calculations performed in QED. For a more thorough study of this phenomenon at the Nuclotron (a superconducting accelerator in JINR), preliminary measurements have been carried out with using an electromagnetic calorimeter based on BGO crystals. These results are consistent with the world data. In JINR, in connection with the building of a future accelerator complex NICA, it has become possible to carry out such studies in pp, pA and AA interactions at energies up to 25 A GeV. Our group develops the conception of an heterogeneous electromagnetic calorimeter as “spaghetti” and “shashlik” types based on gadolinium gallium garnet (GaGG) crystals with a low threshold for registration of photons. The first tests of prototypes of them manufactured at JINR on the basis of the GaGG and a mixture of tungstate and copper as an absorber are reported.

scholarly journals POLARIZATION OBSERVABLES FOR K+Λ AND K+Σ0 PHOTOPRODUCTION FROM POLARIZED PROTONS

2014 ◽  
Vol 26 ◽  
pp. 1460098
Author(s):  
◽  
NATALIE K. WALFORD ◽  
FRANZ J. KLEIN
Keyword(s):  
Excited States ◽  
Final States ◽  
Polarization Data ◽  
Polarized Protons ◽  
Model Predictions ◽  
Double Polarization ◽  
Model Independent ◽  
Polarization Observables ◽  
Large Effort ◽  
Polarized Photons

The search for undiscovered excited states of the nucleon continues to be a focus of experiments at Jefferson Lab. Recent LQCD calculations have confirmed long-standing quark-model predictions of many more states than have so far been identified.1 A large effort for the N* program has been launched using the CLAS detector to provide the database that will allow nearly model-independent partial wave analyses to be carried out in the search for such states. Polarization observables play a crucial role in this effort, as they are essential in disentangling overlapping resonant and non-resonant amplitudes. In 2010, double-polarization data were taken at JLab using circularly polarized photons incident on a transversely polarized frozen-spin butanol target.2 Our current analysis yields preliminary data of the T and F asymmetries of the K+Λ and K+Σ0 final states, which are compared to predictions of recent multipole analyses. This work is the first of its kind and will significantly broaden the world database for these reactions.

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

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