14 research outputs found
The influence of morphological parameters of incubation eggs on the growth and development of repair young
The purpose of the research was to analyze the influence of morphometric parameters of eggs on the quality of day-old chickens, as well as the growth and development of repair young. The shape index of eggs weighing up to 55 g varied from 0.581 to 0.814, in eggs weighing - from 55g to 65 g from 0.687 to 0.805 units. All the eggs under study, having an optimal weight (55-65 g) in terms of suitability for incubation, were divided into 3 groups depending on the size of the shape index: group 1 – 0.687-0.725; group 2 – 0.726-0.764; group 3 – 0.765-0.805. The live weight of day-old chickens in the first group ranged from 31.81 g to 35.47 g, with a coefficient of variation of 3.5%, and in the second, third and fourth groups from 37.12 g to 42.81 g with a coefficient of variation of 3.8%, 4.1% and 6.2%. The weight of day-old chickens of the second group was significantly higher than in the third and fourth groups by 1.4% and 1.2%, respectively. At the age of 17 weeks, the difference in the live weight of the repair young between the second, third and fourth groups was not significant and ranged from 0.14% to 0.38%, and in average daily increments from 0.05% to 1.16%. The repair young of the first group were significantly inferior to their peers in terms of live weight by 207.48-213.94 g, and in terms of average daily gains - by 15.5-14.5%. The safety of livestock was: group 1 - 89.6%; group 2 - 98.7%; 3 - 97.3; group 4 - 97.5%. The uniformity of poultry by live weight in the groups was 80.2-85.7%
Measurement of and between 3.12 and 3.72 GeV at the KEDR detector
Using the KEDR detector at the VEPP-4M collider, we have measured
the values of and at seven points of the center-of-mass
energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or
better than at most of energy points with a systematic uncertainty of
about . At the moment it is the most accurate measurement of in
this energy range
Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector
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.)
Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)
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 figure
Measurement of main parameters of the \psi(2S) resonance
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
Gardens, Chinese: Wang Shi Yuan Garden, Suzhou, China [068]
Photograph of a screen with image of bamboo, Wang Shi Yuan Garden, Suzhou, ChinaScreen detail with image of bamboo, Wang Shi Yuan Garden, Suzhou, China
Final analysis of KEDR data on J/ψ and ψ(2S) masses
We present the analysis of all KEDR data on the determination of J/ψ and ψ(2S) masses. The data comprise six scans of J/ψ and seven scans of ψ(2S) which were performed at the VEPP-4M e+e− collider in 2002–2008. The beam energy was determined using the resonance depolarization method. The detector and accelerator conditions during scans were very different that increases the reliability of the averaged results. The analysis accounts for partial correlations of systematic uncertainties on the masses. The following mass values were obtained:MJ/ψ=3096.900±0.002±0.006 MeV,Mψ(2S)=3686.099±0.004±0.009 MeV. These results supersede our previous measurements published in 2003 and 2012
Recent Results from the KEDR Detector
We describe recent results from the KEDR detector at the VEPP-4Mcollider. They include: a search for narrow resonances between 1.85 and 3.1 GeV, a test of leptonic universality by comparing partial widths of the J/ψ resonance into electron and muon pairs, a determination of the main parameters of the ψ(2S) and a measurement of ψ(3770) parameters