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A. N. Khrenov

Publications and source records attributed to A. N. Khrenov.

15 recordsLinked to original sources

Deuteron analyzing powers $A_y$, $A_{yy}$ and $A_{xx}$ in dp-elastic scattering at large transverse momenta

The results on the the vector $A_y$, $A_{yy}$ and $A_{xx}$ analyzing powers in deuteron-proton elastic scattering at large scattering angles are presented. These data were obtained at internal target at JINR Nuclotron in the energy range 400-1800 MeV using polarized deuteron beam from new polarized ion source. New data on the deuteron analyzing powers in the wide energy range demonstrate the sensitivity to the short-range spin structure of the isoscalar nucleon-nucleon correlations.

nucl-ex↗

Conceptual design of the Spin Physics Detector

The Spin Physics Detector, a universal facility for studying the nucleon spin structure and other spin-related phenomena with polarized proton and deuteron beams, is proposed to be placed in one of the two interaction points of the NICA collider that is under construction at the Joint Institute for Nuclear Research (Dubna, Russia). At the heart of the project there is huge experience with polarized beams at JINR. The main objective of the proposed experiment is the comprehensive study of the unpolarized and polarized gluon content of the nucleon. Spin measurements at the Spin Physics Detector at the NICA collider have bright perspectives to make a unique contribution and challenge our understanding of the spin structure of the nucleon. In this document the Conceptual Design of the Spin Physics Detector is presented.

hep-ex↗

Measurement of the deuteron beam polarization at internal target at Nuclotron for DSS experiment

The current deuteron beam polarimetry at Nuclotron is provided by the Internal Target polarimeter based on the use of the asymmetry in dp- elastic scattering at large angles in the cms at 270 MeV. The upgraded deuteron beam polarimeter has been used obtain the vector and tensor polarization during 2016/2017 runs for the DSS experimental program. The polarimeter has been used also for tuning of the polarized ion source parameters for 6 different spin modes.

physics.ins-det↗

First results on the measurements of the proton beam polarization at internal target at Nuclotron

The spin program at NICA using SPD and MPD requires high intensity polarized proton beam with high value of the beam polarization. First results on the measurements of the proton beam polarization performed at internal target at Nuclotron are reported. The polarization of the proton beam provided by new source of polarized ions has been measured at 500 MeV using quasielastic proton-proton scattering and DSS setup at internal target. The obtained value of the vertical polarization of ~35 % is consistent with the calculations taking into account the current magnetic optics of the Nuclotron injection line.

physics.ins-det↗

Study of the dp-elastic scattering at 2 GeV

The results on the measurements of dp-elastic scattering cross section at the energy 2 GeV at Internal Target Station at the Nuclotron JINR are reported. The data were obtained for the angular range of 70-107 deg. in the c.m.s. by using CH2 and C targets. The results are compared with the existing data and with the theoretical calculations based on the relativistic multiple scattering theory.

nucl-ex↗

Measurement of the vector and tensor analyzing powers for dp- elastic scattering at 880 MeV

The vector Ay and tensor analyzing powers Ayy and Axx for dp- elastic scattering were measured at Td = 880 MeV over the c.m. angular range from 60 to 140 degrees at the JINR Nuclotron. The data are compared with predictions of different theoretical models based on the use of nucleon-nucleon forces only. The observed discrepancies of the measured analyzing powers from the calculations require the consideration of additional mechanisms.

nucl-ex↗

The light nuclei spin structure from hadronic channels at intermediate energies

The investigation of the d, 3H and 3He spin structure has been performed at the RIKEN(Japan) accelerator research facility and VBLHEP(JINR) using both polarized and unpolarized deuteron beams. The experimental results on the analyzing powers studies in dp- elastic scattering, d(d,3H)p and d(d,3He)n reactions are presented. The vector and tensor analyzing powers for dp-elastic scattering at 880 and 2000 MeV are obtained at the Nuclotron(VBLHEP). The result on the analyzing powers Ay, Ayy of the deuteron at 2000 MeV are compared with relativistic multiple scattering model calculations. The data on the tensor analyzing powers for the d(d,3H)p and d(d,3He)n reactions obtained at Ed = 200 and 270 MeV demonstrate the sensitivity to the 3H, 3He and deuteron spin structure. The essential disagreements between the experimental results and the theoretical calculations within the one-nucleon exchange model framework are observed. The wide experimental program on the study of the polarization effects in dp- elastic scattering, dp-nonmesonic breakup, d(d,3He)n, d(d,3H)p and d(3He,4He)p reactions using internal and extracted beam at Nuclotron is discussed.

nucl-ex↗

The 270 MeV deuteron beam polarimeter at the Nuclotron Internal Target Station

A deuteron beam polarimeter has been constructed at the Internal Target Station at the Nuclotron of JINR. The polarimeter is based on spin-asymmetry measurements in the d-p elastic scattering at large angles and the deuteron kinetic energy of 270 MeV. It allows to measure vector and tensor components of the deuteron beam polarization simultaneously.

nucl-ex↗

Tensor Ayy and vector Ay analyzing powers in the H(d,d')X and ^{12}C(d,d')X reactons at initial deuteron momenta of 9 GeV/c in the region of baryonic resonances excitation

The angular dependence of the tensor Ayy and vector Ay analyzing powers in the inelastic scattering of deuterons with a momentum of 9.0 GeV/c on hydrogen and carbon have been measured. The range of measurements corresponds to the baryonic resonance excitation with masses 2.2--2.6 GeV/c^2. The Ayy data being in good agreement with the previous results demonstrate an approximate $t$ scaling up to -1.5 (GeV/c)^2. The large values of A_y show a significant role of the spin-dependent part of the elementary amplitude of the NN->NN* reaction. The results of the experiment are compared with model predictions of the plane-wave impulse approximation.

nucl-ex↗

Tensor Ayy and Vector Ay Analyzing Powers of the (d,p) and (d,d) Reactions at 5 Gev/c and 178 MR

New data on the tensor analyzing power Ayy of the ^9Be(d,p)X reaction at an initial deuteron momentum of 5 GeV/c and secondary particles (protons and deuterons) detection angle of 178 mr have been obtained at the JINR Synchrophasotron. The proton data obtained are analyzed within the framework of an approach based on the light-front dynamics using Karmanov's relativistic deuteron wave function. Contrary to the calculations with standard non-relativistic deuteron wave functions, we have managed to explain the new data within the framework of our approach without invoking degrees of freedom additional to nucleon ones. The ^9Be(d,d)X data are obtained in the vicinity of the excitation of baryonic resonances with masses up to 1.8 GeV/c^2. The Ayy data are in a good agreement with the previous data obtained at 4.5 and 5.5 GeV/c when they are plotted versus $t$. The results of the experiment are compared with the predictions of the plane wave impulse approximation and ω-meson exchange models.

nucl-ex↗

Investigation of the Angular Dependence of the Tensor Analyzing Power of 9 Gev/C Deuteron Breakup

An angular dependence of the tensor analyzing power of the breakup of polarized deuterons at 9 GeV/$c$ has been investigated. The measurements have been made on hydrogen and carbon targets at angles in the range from 85 to 160 mr. The data obtained are analyzed within the framework of the light-front dynamics using the deuteron wave functions for Paris and Bonn CD potentials, and the relativistic deuteron wave function by Karmanov et al. The experimental data are in rough agreement with calculations with the use of Karmanov's deuteron wave function.

nucl-ex↗

Tensor analyzing power Ayy in deuteron inclusive breakup at large Pt and spin structure of deuteron at short internucleonic distances

The Ayy data for deuteron inclusive breakup off hydrogen and carbon at a deuteron momentum of 9.0 GeV/c and large Pt of emitted protons are presented. The large values of Ayy independent of the target mass reflect the sensitivity of the data to the deuteron spin structure. The data obtained at fixed $x$ and plotted versus Pt clearly demonstrate the dependence of the deuteron spin structure at short internucleonic distances on two variables. The data are compared with the calculations using Paris, CD-Bonn and Karmanov's deuteron wave functions.

nucl-ex↗

Measurement of the Extracted Deuteron Beam Vector Polarization at Nuclotron

The results of the measurements of the vector polarization of the extracted deuteron beam at Nuclotron are presented. The intensity of the polarized deuteron beam during the measurements was 2.5*10^7 particles/spill. The measurements were made at the initial deuteron momenta of 5 and 3.5 GeV/c. The averaged polarizations of the beam were 0.606 +/- 0.014 and 0.540+/- 0.019, respectively.

nucl-ex↗

Measurement of the tensor Ayy and vector Ay analyzing powers of the deuteron inelastic scattering off berillium at 5.0 GeV/c and 178 mr

Tensor Ayy and vector Ay analyzing powers in the inelastic scattering of deuterons with the momentum of 5.0 GeV/c on beryllium at an angle of 178 mr in the vicinity of the excitation of baryonic resonances with masses up to 1.8 GeV/c^2 have been measured. The Ayy data are in a good agreement with the previous data obtained at 4.5 and 5.5 GeV/c. The results of the experiment are compared with the predictions of the plane wave impulse approximation and ω-meson exchange models.

nucl-ex↗