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L. M. Barkov,
V. V. Gauzshtein,
V. F. Dmitriev, B. A. Lazarenko,
M. I. Levchuk,
A. Yu. Loginov,
S. I. Mishnev,
D. M. Nikolenko,
A. V. Osipov,
I. A. Rachek,
A. A. Sidorov,
V. N. Stibunov,
D. K. Toporkov,
Yu. V. Shestakov,
S. A. Zevakov
[show abstract]
[hide abstract]
ABSTRACT: The tensor asymmetry of exclusive π−-meson photoproduction on polarized deuterons was investigated. The T
20 and T
22 components of the reaction analyzing power contribute to the measured asymmetry. The detector made it possible to record
two outgoing protons in coincidence in the range of polar angles θ1,2 = 44° − 88° and in the momentum range p
1,2 = 350 − 700 MeV c
−1. The measurements were performed at the VEPP-3 storage ring (Novosibirsk) using an internal target. The experimental results
are compared with theoretical calculations.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 74(6):743-746.
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D. M. Nikolenko,
L. M. Barkov,
V. F. Dmitriev,
S. A. Zevakov, B. A. Lazarenko,
S. I. Mishnev,
A. V. Osipov,
I. A. Rachek,
R. Sh. Sadykov,
V. N. Stibunov,
D. K. Toporkov,
Yu. V. Shestakov
[show abstract]
[hide abstract]
ABSTRACT: The components of the tensor analyzing powers, T
20, T
21, and T
22, of the coherent photoproduction of a π0 meson on a deuteron have been measured for photon energies of 250–450 MeV and pion emission angles of 90°–145°. The results
are compared with the theoretical predictions.
JETP Letters 04/2012; 89(9):432-436. · 1.35 Impact Factor
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D. M. Nikolenko,
H. Arenhövel,
J. Arrington,
L. M. Barkov,
S. L. Belostotski,
H. de Vries,
R. Gilman,
A. V. Gramolin,
V. F. Dmitriev,
S. A. Zevakov, [......],
V. V. Nelyubin,
A. V. Osipov,
D. H. Potterveld,
I. A. Rachek,
R. Sh. Sadykov,
V. N. Stibunov,
D. K. Toporkov,
R. J. Holt,
Yu. V. Shestakov,
L. I. Shekhtman
[show abstract]
[hide abstract]
ABSTRACT: An overview of the recently completed, current, and planned experiments with internal targets at the VEPP-3 electron-positron
storage ring in Novosibirsk is given. The results of the experiment to separately measure the deuteron form factors in elastic
ed scattering in the range of momentum transfer Q
2 = 8−15 fm−2 are provided. The results of measuring the tensor analyzing power components of the tensor-polarized deuteron photodisintegration
reaction in the range of γ-quantum energies E
γ
= 25−600 MeV are presented. The tensor analyzing powers of the coherent photoproduction of a neutral pion on a tensor-polarized
deuteron have been measured for the first time. The almost-real photon tagging system being created is discussed. The status
of the experiment under way to determine the contribution of two-photon exchange to the elastic ep scattering cross section is described.
Physics of Atomic Nuclei 04/2012; 73(8):1322-1338. · 0.57 Impact Factor
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A. V. Gramolin,
J. Arrington,
L. M. Barkov,
V. F. Dmitriev,
V. V. Gauzshtein,
R. A. Golovin,
R. J. Holt,
V. V. Kaminsky, B. A. Lazarenko,
S. I. Mishnev, [......],
V. V. Neufeld,
D. M. Nikolenko,
I. A. Rachek,
R. Sh. Sadykov,
Yu. V. Shestakov,
V. N. Stibunov,
D. K. Toporkov,
H. de Vries,
S. A. Zevakov,
V. N. Zhilich
[show abstract]
[hide abstract]
ABSTRACT: We report on the status of the Novosibirsk experiment on a precision
measurement of the ratio $R$ of the elastic $e^+ p$ and $e^- p$ scattering
cross sections. Such measurements determine the two-photon exchange effect in
elastic electron-proton scattering. The experiment is conducted at the VEPP-3
storage ring using a hydrogen internal gas target. The ratio $R$ is measured
with a beam energy of 1.6 GeV (electron/positron scattering angles are $\theta
= 55 \div 75^{\circ}$ and $\theta = 15 \div 25^{\circ}$) and 1 GeV ($\theta =
65 \div 105^{\circ}$). We briefly describe the experimental method, paying
special attention to the radiative corrections. Some preliminary results are
presented.
12/2011;
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I A Rachek,
H Arenhövel,
L M Barkov,
S L Belostotsky,
V F Dmitriev,
V V Gauzshteyn,
R Gilman,
A V Gramolin,
R J Holt, B A Lazarenko, [......],
A V Osipov,
D H Potterveld,
R Sh Sadykov,
L I Shekhtman,
Yu V Shestakov,
A A Sidorov,
V N Stibunov,
D K Toporkov,
H De Vries,
S A Zevakov
[show abstract]
[hide abstract]
ABSTRACT: We give an overview of the activity in studying photoprocesses on a tensor-polarized deuterium target, which is carried out at the VEPP–3 electron storage ring. Recent experimental results on tensor asymmetries in two-body deuteron photodisintegration at the photon energy up to 500 MeV, and in coherent pion photoproduction on deuteron are presented. Plans to upgrade the facility and future experiments are discussed. Further progress is connected with the installation of a tagging system for almost–real photons. This would allow us to extend the measurements of polarization observables in photonuclear reactions on deuteron up to a photon energy of 1.5 GeV and permit to perform double polarized experiments – with linear polarized photon beams and tensor/vector polarized deuterium targets.
Journal of Physics Conference Series 01/2011; 295:012106.
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D M Nikolenko,
J Arrington,
L M Barkov,
V F Dmitriev,
V V Gauzshteyn,
R A Golovin,
A V Gramolin,
R J Holt,
V V Kaminsky, B A Lazarenko, [......],
A V Osipov,
I A Rachek,
R Sh,
Sadykov,
Yu V Shestakov,
V N Stibunov,
D K Toporkov,
H De Vries,
S A Zevakov,
V N Zhilich
[show abstract]
[hide abstract]
ABSTRACT: We report the experiment on a precise comparison of (e + p) and (e − p) elastic scattering cross sections, which gives a direct experimental evidence for the two-photon exchange contribution to this reaction. Such data are in demand now, because they, most likely, may explain the dra-matic disagreement of proton electromagnetic form factors measurements in the polarization transfer experiments at TJNAF with previous unpolarized measurements using a Rosenbluth sep-aration technique. Experiment was performed recently at VEPP–3 storage ring at the energy of positron/electron beams of 1.6 GeV and at e + /e − scattering angles around 20 • and 65 • . The preliminary results for the cross sections ratio R = σ (e + p)/σ (e − p) are presented.
PoS. 01/2010;
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I A Rachek,
L M Barkov,
S L Belostotsky,
V F Dmitriev,
M V Dyug,
R Gilman,
R J Holt, B A Lazarenko,
S I Mishnev,
V V Nelyubin,
D M Nikolenko,
A V Osipov,
D H Potterveld,
R Sh Sadykov,
Yu V Shestakov,
V N Stibunov,
D K Toporkov,
H de Vries,
S A Zevakov
[show abstract]
[hide abstract]
ABSTRACT: A new accurate measurement of the tensor analyzing powers T20, T21, and T22 in deuteron photodisintegration has been performed. Wide-aperture nonmagnetic detectors allowed broad kinematic coverage in a single set up: E(gamma)=25 to 600 MeV, and theta(p)(cm)=24 degrees to 48 degrees and 70 degrees to 102 degrees . The new data provide a significant improvement over the few existing measurements. The angular dependency of the tensor asymmetries in deuteron photodisintegration is extracted for the first time.
Physical Review Letters 06/2007; 98(18):182303. · 7.37 Impact Factor
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D M Nikolenko,
H Arenhövel,
L M Barkov,
S L Belostotsky,
V F Dmitriev,
M V Dyug,
R Gilman,
R J Holt,
L G Isaeva,
C W de Jager, [......],
D H Potterveld,
I A Rachek,
R Sh Sadykov,
Yu V Shestakov,
A A Sidorov,
V N Stibunov,
D K Toporkov,
V V Vikhrov,
H de Vries,
S A Zevakov
[show abstract]
[hide abstract]
ABSTRACT: The tensor analyzing power components T20 and T21 have been measured in elastic electron-deuteron scattering at the 2 GeV electron storage ring VEPP-3, Novosibirsk, in a four-momentum transfer range from 8.4 to 21.6 fm(-2). A new polarized internal gas target with an intense cryogenic atomic beam source was used. The new data determine the deuteron form factors G(C) and G(Q) in an important range of momentum transfer where the first node of the deuteron monopole charge form factor is located. The new results are compared with previous data and with some theoretical predictions.
Physical Review Letters 03/2003; 90(7):072501. · 7.37 Impact Factor
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M V Dyug,
L G Isaeva, B A Lazarenko,
S I Mishnev,
D M Nikolenko,
I A Rachek,
Yu V Shestakov,
R Sh,
Sadykov,
D K Toporkov,
S A Zevakov,
A V Osipov,
V N Stibunov
[show abstract]
[hide abstract]
ABSTRACT: Description of the polarized deuterium gas target used at the VEPP-3 electron storage ring for experiments on elastic and inelastic ed scattering is given. Superconducting sextupole magnets with the pole tip magnetic field up to 4:8 T are used in atomic beam source (ABS) to focus atoms. The flux of polarized atoms injected into the storage cell was measured to be 8:2 Â 10 16 at=s for deuterium and 7:9 Â 10 16 at=s for hydrogen. The measured target thickness 8 Â 10 13 at=cm 2 is consistent with the thickness calculated from the measured beam intensity. The effective tensor polarization of the deuterium target during the experiment was found to be P zz ¼ 0:397: Further improvements of the target and possible limitation of the beam intensity from ABS are discussed. r 2002 Elsevier Science B.V. All rights reserved.
Nuclear Instruments and Methods in Physics Research A. 01/2002; 495252520(29).
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L. G. Isaeva, B. A. Lazarenko,
S. I. Mishnev,
D. M. Nikolenko,
A. N. Osipov,
S. G. Popov,
I. A. Rachek,
Yu. V. Shestakov,
A. A. Sidorov,
V. N. Stibunov,
D. K. Toporkov,
D. K. Vesnovsky,
S. A. Zevakov
[show abstract]
[hide abstract]
ABSTRACT: The experiment on elastic and inelastic scattering of 2 GeV electrons by internal polarized target is in progress at the VEPP-3 storage ring in Novosibirsk. It’s carried out by Novosibirsk/St.-Petersburg/Tomsk/Argonne/Illinois/NIKHEF collaboration. A cryogenic Atomic Beam Source having five superconducting sextupoles is under manufacturing to feed by polarized deuterium atoms an internal storage cell target. All the magnets have been manufactured and tested. The magnetic poletip field up to 4.8 T was measured at the cylindrical magnets having 44 mm inner diameter while 3.1 T and 4.0 T were measured for the tapered magnets. The dissociation degree of about 90% has been achieved for a gas throughput 1 mb×1/sec. The expected flux of polarized deuterium atoms into the storage cell is 1.0×1017 at/sec (in two substrates). The geometry of the magnetic system, results on the dissociation measurements, testing of the superconducting magnet and expected parameters of the target are presented. © 1998 American Institute of Physics.
AIP Conference Proceedings. 01/1998; 421(1):109-118.
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M.V. Dyug,
A.V. Grigoriev,
V.A. Kiselev, B.A. Lazarenko,
E.B. Levichev,
A.I. Mikaiylov,
S.I. Mishnev,
S.A. Nikitin,
D.M. Nikolenko,
I.A. Rachek,
Yu.V. Shestakov,
D.K. Toporkov,
S.A. Zevakov,
V.N. Zhilich
[show abstract]
[hide abstract]
ABSTRACT: A new method to determine the polarization of an electron beam circulating in a storage ring by a non-destructive way, based on measuring the asymmetry in scattering of beam electrons on electrons of the internal polarized gas jet target, has been developed and tested at the VEPP-3 storage ring.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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[show abstract]
[hide abstract]
ABSTRACT: Experiments on electron scattering from polarized deuterons were carried out on the VEPP-3 storage ring at the Novosibirsk Institute for Nuclear Physics. The e—D coincidences were detected for elastic scattering experiments, and the p—n coincidences for photo disintegration studies. The tensor analyzing power of the elastic scattering was measured in the range of momentum transfer up to 3 f−1, and of photo disintegration in the range of photon energy up to 500 MeV. The detector system created for these experiments and the data analysis procedures are described in this paper.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
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M.V. Dyug, B.A. Lazarenko,
S.I. Mishnev,
D.M. Nikolenko,
I.A. Rachek,
Yu.V. Shestakov,
R.Sh. Sadykov,
D.K. Toporkov,
S.A. Zevakov,
A.N. Osipov,
V.N. Stibunov
[show abstract]
[hide abstract]
ABSTRACT: The polarimeter for the internal tensor polarized deuterium gas target is described. Polarimeter is based on a target asymmetry measurement of elastic ed-scattering at a small momentum transfer. It was used in elastic and inelastic scattering experiments at VEPP-3 electron storage ring.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
