-
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;
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. Yu. Basok,
O. L. Beloborodova,
A E Blinov, [......],
V I Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A N Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We report a new precise determination of the leptonic widths of the J/psi
meson performed with the KEDR detector at the VEPP-4M $e^{+}e^{-}$ collider.
The measured values of the J/psi parameters are:
\Gamma_{ee}\times\Gamma_{ee}/\Gamma = 0.3323 \pm 0.0064 (stat.) \pm 0.0048
(syst.) keV \Gamma_{ee}\times\Gamma_{\mu\mu}/\Gamma=0.3318 \pm 0.0052 (stat.)
\pm 0.0063 (syst.) keV. Assuming $e\mu$ universality and using the table value
of the branching ratios the leptonic \Gamma_{ll}= 5.59 \pm 0.12 keV width and
the total \Gamma=94.1 \pm 2.7 keV widths were obtained. We also discuss in
detail a method to calculate radiative corrections at a narrow resonance.
10/2011;
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. Yu. Basok,
O. L. Beloborodova,
A. E. Blinov, [......],
V. I. Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A. N. Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We report the final results of a study of the \psi(3770) meson using a data
sample collected with the KEDR detector at the VEPP-4M electron-positron
collider. The data analysis takes into account the interference between the
resonant and nonresonant $D\bar{D}$ production, where the latter is related to
the nonresonant part of the energy-dependent form factor $F_D$. The vector
dominance approach and several empirical parameterizations have been tried for
the nonresonant $F_D^{\NR}(s)$.
Our results for the mass and total width of \psi(3770) are
M = 3779.2 ^{+1.8}_{-1.7} ^{+0.5}_{-0.7} ^{+0.3}_{-0.3} MeV, \Gamma =24.9
^{+4.6}_{-4.0} ^{+0.5}_{-0.6} ^{+0.2}_{-0.9} MeV, where the first, second and
third uncertainties are statistical, systematic and model, respectively. For
the electron partial width two possible solutions have been found:
(1) \Gamma_{ee} = 154 ^{+79}_{-58} ^{+17}_{-9} ^{+13}_{-25} eV, (2)
\Gamma_{ee} = 414 ^{+72}_{-80} ^{+24}_{-26} ^{+90}_{-10} eV.
Our statistics are insufficient to prefer one solution to another. The
solution (2) mitigates the problem of non-$D\bar{D}$ decays but is disfavored
by potential models.
It is shown that taking into account the resonance--continuum interference in
the near-threshold region affects resonance parameters, thus the results
presented can not be directly compared with the corresponding PDG values
obtained ignoring this effect.
09/2011;
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. Yu. Basok,
O. L. Beloborodova,
A. E. Blinov, [......],
V. I. Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A. N. Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: A high-precision determination of the main parameters of the \psi(2S)
resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-}
collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the
energy dependence of the multihadron cross section in the vicinity of the
\psi(2S) we obtained the mass value
M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the
electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h}
= 2.233 +- 0.015 +- 0.037 +- 0.020 keV.
The third error quoted is an estimate of the model dependence of the result
due to assumptions on the interference effects in the cross section of the
single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this
work.
Implicitly, the same assumptions were employed to obtain the charmonium
leptonic width and the absolute branching fractions in many experiments.
Using the result presented and the world average values of the electron and
hadron branching fractions, one obtains the electron partial width and the
total width of the \psi(2S):
\Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV,
\Gamma = 296 +- 2 +- 8 +- 3 keV.
These results are consistent with and more than two times more precise than
any of the previous experiments.
09/2011;
-
KEDR Collaboration,
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. Yu. Basok,
O. L. Beloborodova, [......],
V I Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A N Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We report results of a search for narrow resonances in e+ e- annihilation at
center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR
detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width
of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained
(at 90 % C.L.).
07/2011;
-
[show abstract]
[hide abstract]
ABSTRACT: The tagging system (TS) of the KEDR detector is designed for study of two-photon interactions on the VEPP-4M electron-positron collider. The upgrade of the TS was completed and 8 triple-GEM detectors were added to the system with a single detector sensitive area up to 250*100 mm2, a spatial resolution in the beam orbit plane close to 70 μm and a small angle stereo readout providing a resolution of around 200 μm in perpendicular direction. The triple-GEM detectors were included into the KEDR DAQ system, and since the beginning of the 2010-2011 season they have demonstrated stable operation at a gas gain of 20000–40000 and efficiency of 95–97%. The new detectors will allow performing background suppression and improving the energy resolution of the system.
Journal of Instrumentation 06/2011; 6(07):P07001. · 1.87 Impact Factor
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. Yu. Basok,
I. V. Bedny,
O. L. Beloborodova, [......],
V I Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A N Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and mass. Taking into account an asymmetric photon line shape we obtain: M(eta_c) = (2978.1 +- 1.4 +- 2.0) MeV/c^2, Gamma(eta_c) = (43.5 +- 5.4 +- 15.8) MeV, B(J/psi->eta_c gamma) = (2.59 +- 0.16 +- 0.31)%$. Comment: 6 pages, 1 figure. To be published in the proceedings of the 4th International Workshop on Charm Physics (Charm2010), October 21-24, 2010, IHEP, Beijing
12/2010;
-
MO Xiao-Hu,
E. V. Abakumova,
M. N. Achasov,
V. E. Blinov,
CHU Yuan-Ping,
DONG Hai-Yi,
FU Cheng-Dong,
F. A. Harris,
V. V. Kaminskiy,
A. A. Krasnov, [......],
G. S. Varner,
WANG Yi-Fang,
XU Jin-Qiang,
ZHANG Jian-Yong,
ZHANG Qing-Jiang,
ZHANG Yin-Hong,
ZHANG Tian-Bao, V. N. Zhilich,
ZHAO Zhuo,
A. A. Zhukov
[show abstract]
[hide abstract]
ABSTRACT: The beam energy measurement system at BEPCII is composed of there parts: laser source and optics system, laser-electron interaction system and High Purity Germanium (HPGe) detector system. The special components and construction of each part are introduced, especially about radiation background measurement in the storage ring, which is of great importance for the safe commissioning of HPGe detector.
Chinese Physics C 06/2010; 34(6):912. · 0.27 Impact Factor
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. V. Bedny,
O. L. Beloborodova,
A. E. Blinov, [......],
V. I. Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A. N. Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e+e− collider. We measure the branching fraction of radiative decay J/ψ → ηcγ, ηc width and mass. Our preliminary results are: M(ηc) = 2979.4±1.5±1.9 MeV/c2, Γ(ηc) = 27.8±5.1±3.3 MeV, Γ(J/ψ→ ηcγ) = (2.34±0.15±0.40)%.
Chinese Physics C 06/2010; 34(6):831. · 0.27 Impact Factor
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. V. Bedny,
O. L. Beloborodova,
A. E. Blinov, [......],
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A. N. Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev,
KEDR Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The products of the electron width of the J/ψ meson and the
branching fraction of its decays to the lepton pairs were measured using
data from the KEDR experiment at the VEPP-4M electron-positron collider.
The results are
Γ×Γ/Γ=0.3323±0.0064(stat.)±0.0048(syst.)
keV,
Γ×Γ/Γ=0.3318±0.0052(stat.)±0.0063(syst.)
keV. Their combinations
Γ×(Γ+Γ)/Γ=0.6641±0.0082(stat.)±0.0100(syst.)
keV,
Γ/Γ=1.002±0.021(stat.)±0.013(syst.)
can be used to improve the accuracy of the leptonic and full widths and
test leptonic universality. Assuming eμ universality and using the
world average value of the lepton branching fraction, we also determine
the leptonic Γ=5.59±0.12 keV and total
Γ=94.1±2.7 keV widths of the J/ψ meson.
Physics Letters B 02/2010; 685:134-140. · 3.95 Impact Factor
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. V. Bedny,
O. L. Beloborodova,
A E Blinov, [......],
V I Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A N Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We present a study of the inclusive photon spectra from 5.9 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c width and mass. Our preliminary results are: M(eta_c) = 2979.4+-1.5+-1.9 MeV, G(eta_c) = 27.8+-5.1+-3.3 MeV, B(J/psi to eta_c gamma) = (2.34+-0.15+-0.40)%. Comment: To be published in Proceedings of the PhiPsi09, Oct. 13-16, 2009, Beijing, China
02/2010;
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. V. Bedny,
O. L. Beloborodova,
A E Blinov, [......],
V I Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A N Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: We report results of experiments performed with the KEDR detector at the VEPP-4M e+e- collider. They include precise measurement of the D0 and D+- meson masses, determination of the psi(3770) resonance parameters, and a search for narrow resonances in e+e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV. Comment: To be published in Proceedings of the PhiPsi09, Oct. 13-16, 2009, Beijing, China
01/2010;
-
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;
-
KEDR Collaboration,
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. V. Bedny,
O. L. Beloborodova, [......],
V I Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A N Yushkov, V. N. Zhilich,
V. V. Zhulanov,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson. Comment: 7 pages, 6 figures
12/2009;
-
[show abstract]
[hide abstract]
ABSTRACT: The VEPP-4M electron-positron collider is now operating with the KEDR detector for the experiment of precise measurement of tau-lepton mass. In this experiment, monitoring of beam energy spread is important to know the energy spread contribution into the total systematic error. Information about the energy spread gives an opportunity to reduce the error of the tau-lepton mass measurement. Several techniques for energy spread measurement are described in the paper. Width of the ψ' resonance measured with the KEDR detector is used as a reference.
Journal of Instrumentation 06/2007; 2(06):P06001. · 1.87 Impact Factor
-
V. V. Anashin,
V. M. Aulchenko,
E. M. Baldin,
A. K. Barladyan,
A. Yu. Barnyakov,
M. Yu. Barnyakov,
S. E. Baru,
I. V. Bedny,
O. L. Beloborodova,
A. E. Blinov, [......],
V. A. Tayursky,
V. I. Telnov,
Yu. A. Tikhonov,
K. Yu. Todyshev,
G. M. Tumaikin,
Yu. V. Usov,
A. I. Vorobiov,
A. N. Yushkov, V. N. Zhilich,
A. N. Zhuravlev
[show abstract]
[hide abstract]
ABSTRACT: A precise τ lepton mass measurement performed at the VEPP-4M collider with the KEDR detector is reported. The mass value is
evaluated from the τ+τ− cross section behavior around the production threshold. The result based on 6.7 pb−1 of data is m
τ = 1776.81
−0.23
+0.25
± 0.15 MeV. Using 0.8 pb−1 of data collected at the ψ′ peak, we have also determined that Γ
ee
B
ττ(ψ′) = 9.0 ± 2.6 eV.
JETP Letters 05/2007; 85(8):347-352. · 1.35 Impact Factor
-
V.E. Blinov,
A.V. Bogomyagkov,
S.E. Karnaev,
V.A. Kiselev,
E.B. Levichev,
S.I. Mishnev,
S.A. Nikitin,
I.B. Nikolaev,
D.M. Nikolenko,
I.Ya. Protopopov,
Yu.A. Tikhonov,
D.K. Toporkov,
G.M. Tumaikin, V.N. Zhilich,
N.I. Zinevich
[show abstract]
[hide abstract]
ABSTRACT: We plan to measure the mass of τ lepton near the threshold of
its production with an accuracy 10<sup>-4</sup> or better in the
experiment with the detector KEDR at the e<sup>+</sup>e<sup>-</sup>
collider VEPP-4M using the method of resonance depolarization for
calibration of particle energy. The scenario of the experiment, the
developed systems of polarimeters and the depolarizer are described.
Some points regarding beam polarization and energy calibration accuracy
are considered
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001; 02/2001
-
S. E. Baru,
A. E. Blinov,
V. E. Blinov,
A. E. Bondar,
A. D. Bukin,
V. R. Groshev,
Yu. I. Eidelman,
V. A. Kiselev,
S. G. Klimenko,
G. M. Kolachev, [......],
V. A. Sidorov,
Yu. I. Skovpen,
A. N. Skrinsky,
V. A. Tayursky,
V. I. Telnov,
Yu. A. Tikhonov,
G. M. Tumaikin,
A. E. Undrus,
A. I. Vorobiov, V. N. Zhilich
[show abstract]
[hide abstract]
ABSTRACT: Experiments with the MD-1 detector at the VEPP-4 collider in the energy region of Υ mesons were carried out in 1980–1985. Some of the MD-1’s results are still among the most accurate: precise measurement of Υ(1S), Υ(2S) and Υ(3S) meson masses; leptonic widths of Υ(1S) and Υ(2S); R ratio in the energy region = 7.2–10.3 GeV; upper limits on the Υ(1S) decays to p, K+K−, π+π−; upper limit on the electron width of new resonances in the energy region 7.2–10.3 GeV. New values of Υ(1S), Υ(2S), and Υ(3S) masses corrected to change of the electron mass are given. © 1998 American Institute of Physics.
AIP Conference Proceedings. 02/1998; 424(1):97-105.
-
A. E. Blinov,
V. E. Blinov,
A. E. Bondar,
A. D. Bukin,
V. R. Groshev,
S. G. Klimenko,
A. P. Onuchin,
V. S. Panin,
I. Ya. Protopopov,
A. G. Shamov,
V. A. Sidorov,
Yu. I. Skovpen,
A. N. Skrinsky,
V. A. Tayursky,
V. I. Telnov,
Yu. A. Tikhonov,
G. M. Tumaikin,
A. E. Undrus,
A. I. Vorobiov, V. N. Zhilich
[show abstract]
[hide abstract]
ABSTRACT: The total cross section of the processe
+
e
− →hadrons has been measured in the center-of-mass energy range between 7.25 and 10.34 GeV using the MD-1 detector at the VEPP-4 collider.
The ratioR=σ(e
+
e
− →hadrons)/σ(e
+
e
− →μ
+
μ
−) was found to be constant in this energy range with the average value of 3.58±0.02±0.14.
Zeitschrift für Physik C 01/1996; 70(1):31-37.
-
A. E. Blinov,
V. E. Blinov,
A. E. Bondar,
A. D. Bukin,
V. R. Groshev,
S. G. Klimenko,
A. P. Onuchin,
V. S. Panin,
I. Ya Protopopov,
A. G. Shamov,
V. A. Sidorov,
Yu. I. Skovpen,
A. N. Skrinsky,
V. A. Tayursky,
V. I. Telnov,
Yu A. Tikhonov,
G. M. Tumaikin,
A. E. Undrus,
A. I. Vorobiov, V. N. Zhilich
[show abstract]
[hide abstract]
ABSTRACT: Bose-Einstein correlations in direct γ(1S) decays and continuum in the energy region √s=7.2−10.3 GeV have been studied using
data taken with the MD-1 detector at VEPP-4 storage ring. Assuming gaussian density of the pion source the data indicate the
radius of the sourceπ=0.73±0.10±0.04 fm for direct γ (1S) decays andπ=0.83±0.22±0.05 fm for the continuum. The correlation strengthsλ for both data samples also are similar. Thus Bose-Einstein correlations do not reveal a noticeable difference between quark
and gluon fragmentation.
Zeitschrift für Physik C 11/1995; 69(1):215-222.
