79 research outputs found
Lifetime distributions in the methods of non-equilibrium statistical operator and superstatistics
A family of non-equilibrium statistical operators is introduced which differ
by the system age distribution over which the quasi-equilibrium (relevant)
distribution is averaged. To describe the nonequilibrium states of a system we
introduce a new thermodynamic parameter - the lifetime of a system.
Superstatistics, introduced in works of Beck and Cohen [Physica A \textbf{322},
(2003), 267] as fluctuating quantities of intensive thermodynamical parameters,
are obtained from the statistical distribution of lifetime (random time to the
system degeneracy) considered as a thermodynamical parameter. It is suggested
to set the mixing distribution of the fluctuating parameter in the
superstatistics theory in the form of the piecewise continuous functions. The
distribution of lifetime in such systems has different form on the different
stages of evolution of the system. The account of the past stages of the
evolution of a system can have a substantial impact on the non-equilibrium
behaviour of the system in a present time moment.Comment: 18 page
Research of the thermal desorption processes in oxide mixtures at laser effect
To investigate the physical-chemical processes occurring during the heating stage of spent nuclear fuel magneto plasma reprocessing a study of thermal desorption of oxides and oxide mixtures as SNF simulators under the influence of stationary laser radiation are being studied. Preliminary experiments were carried out. X-ray diffraction and energy dispersive X-ray microanalysis of the film deposited on the substrate after laser influence on a mixture of BâOâ/ZrOâ oxides have been performed.ĐĐ»Ń ĐČĐžĐČŃĐ”ĐœĐœŃ ŃŃĐ·ĐžĐșĐŸ-Ń
ŃĐŒŃŃĐœĐžŃ
ĐżŃĐŸŃĐ”ŃŃĐČ, ŃĐŸ ĐČŃЎбŃĐČĐ°ŃŃŃŃŃ ĐœĐ° ŃŃĐ°ĐŽŃŃ ĐœĐ°ĐłŃŃĐČŃ ĐŒĐ°ĐłĐœŃŃĐŸĐżĐ»Đ°Đ·ĐŒĐŸĐČĐŸŃ ĐżĐ”ŃĐ”ŃĐŸĐ±ĐșĐž ĐČŃĐŽĐżŃĐ°ŃŃĐŸĐČĐ°ĐœĐŸĐłĐŸ ŃĐŽĐ”ŃĐœĐŸĐłĐŸ палОĐČĐ° (ĐĐŻĐ), ĐżŃĐŸĐČĐŸĐŽĐžŃŃŃŃ ĐŽĐŸŃĐ»ŃĐŽĐ¶Đ”ĐœĐœŃ ĐżŃĐŸŃĐ”ŃŃĐČ ŃĐ”ŃĐŒĐŸĐŽĐ”ŃĐŸŃбŃŃŃ ĐŸĐșŃОЎŃĐČ Ń ĐŸĐșŃĐžĐŽĐœĐžŃ
ŃŃĐŒŃŃĐ”Đč - ŃĐŒŃŃĐ°ŃĐŸŃŃĐČ ĐĐŻĐ ĐżŃĐž ĐČплОĐČŃ ŃŃĐ°ŃŃĐŸĐœĐ°ŃĐœĐŸĐłĐŸ лазДŃĐœĐŸĐłĐŸ ĐČОпŃĐŸĐŒŃĐœŃĐČĐ°ĐœĐœŃ. ĐŃĐŸĐČĐ”ĐŽĐ”ĐœĐŸ ĐżĐŸĐżĐ”ŃĐ”ĐŽĐœŃ Đ”ĐșŃпДŃĐžĐŒĐ”ĐœŃĐž, ĐČĐžĐșĐŸĐœĐ°ĐœŃ ŃĐ”ĐœŃĐłĐ”ĐœĐŸĐŽĐžŃŃĐ°ĐșŃŃĐčĐœĐžĐč Ń Đ”ĐœĐ”ŃĐłĐŸĐŽĐžŃпДŃŃŃĐčĐœĐžĐč ŃĐ”ĐœŃĐłĐ”ĐœŃĐČŃŃĐșĐžĐč ĐŒŃĐșŃĐŸĐ°ĐœĐ°Đ»ŃĐ·Đž плŃĐČĐșĐž, ĐŸŃĐ°ĐŽĐ¶Đ”ĐœĐŸŃ ĐœĐ° ĐżŃĐŽĐșлаЎĐșŃ ĐżŃŃĐ»Ń Đ»Đ°Đ·Đ”ŃĐœĐŸĐłĐŸ ĐČплОĐČŃ ĐœĐ° ŃŃĐŒŃŃ ĐŸĐșŃОЎŃĐČ BâOâ/ZrOâ.ĐĐ»Ń ĐžĐ·ŃŃĐ”ĐœĐžŃ ŃОзОĐșĐŸ-Ń
ĐžĐŒĐžŃĐ”ŃĐșĐžŃ
ĐżŃĐŸŃĐ”ŃŃĐŸĐČ, ĐżŃĐŸĐžŃŃ
ĐŸĐŽŃŃĐžŃ
ĐœĐ° ŃŃаЎОО ĐœĐ°ĐłŃĐ”ĐČĐ° ĐŒĐ°ĐłĐœĐžŃĐŸĐżĐ»Đ°Đ·ĐŒĐ”ĐœĐœĐŸĐč пДŃĐ”ŃĐ°Đ±ĐŸŃĐșĐž ĐŸŃŃĐ°Đ±ĐŸŃĐ°ĐČŃĐ”ĐłĐŸ ŃĐŽĐ”ŃĐœĐŸĐłĐŸ ŃĐŸĐżĐ»ĐžĐČĐ° (ĐĐŻĐą), ĐżŃĐŸĐČĐŸĐŽĐžŃŃŃ ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžĐ” ŃĐ”ŃĐŒĐŸĐŽĐ”ŃĐŸŃбŃОО ĐŸĐșŃĐžĐŽĐŸĐČ Đž ĐŸĐșŃĐžĐŽĐœŃŃ
ŃĐŒĐ”ŃĐ”Đč â ĐžĐŒĐžŃĐ°ŃĐŸŃĐŸĐČ ĐĐŻĐą ĐżŃĐž ĐČĐŸĐ·ĐŽĐ”ĐčŃŃĐČОО ŃŃĐ°ŃĐžĐŸĐœĐ°ŃĐœĐŸĐłĐŸ лазДŃĐœĐŸĐłĐŸ ОзлŃŃĐ”ĐœĐžŃ. ĐŃĐŸĐČĐ”ĐŽĐ”ĐœŃ ĐżŃДЎĐČĐ°ŃĐžŃДлŃĐœŃĐ” ŃĐșŃпДŃĐžĐŒĐ”ĐœŃŃ, ĐČŃĐżĐŸĐ»ĐœĐ”ĐœŃ ŃĐ”ĐœŃĐłĐ”ĐœĐŸĐŽĐžŃŃĐ°ĐșŃĐžĐŸĐœĐœŃĐč Đž ŃĐœĐ”ŃĐłĐŸĐŽĐžŃпДŃŃĐžĐŸĐœĐœŃĐč ŃĐ”ĐœŃĐłĐ”ĐœĐŸĐČŃĐșĐžĐč ĐŒĐžĐșŃĐŸĐ°ĐœĐ°Đ»ĐžĐ·Ń ĐżĐ»Đ”ĐœĐșĐž, ĐŸŃĐ°Đ¶ĐŽĐ”ĐœĐœĐŸĐč ĐœĐ° ĐżĐŸĐŽĐ»ĐŸĐ¶ĐșŃ ĐżŃĐž лазДŃĐœĐŸĐŒ ĐČĐŸĐ·ĐŽĐ”ĐčŃŃĐČОО ĐœĐ° ŃĐŒĐ”ŃŃ ĐŸĐșŃĐžĐŽĐŸĐČ BâOâ/ZrOâ
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 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
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
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
New precise determination of the \tau lepton mass at KEDR detector
The status of the experiment on the precise lepton mass measurement
running at the VEPP-4M collider with the KEDR detector is reported. The mass
value is evaluated from the cross section behaviour around the
production threshold. The preliminary result based on 6.7 pb of data is
MeV. Using 0.8 pb of data
collected at the peak the preliminary result is also obtained:
eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton
Physics, Tau0
Measurement of the branching fraction
The branching fraction is measured in a data sample
corresponding to 0.41 of integrated luminosity collected with the LHCb
detector at the LHC. This channel is sensitive to the penguin contributions
affecting the sin2 measurement from The
time-integrated branching fraction is measured to be . This is the most precise measurement to
date
Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays
Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of
prime importance in probing new physics. Here 7421 +/- 105 signal events from
the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp
collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A
time-dependent fit to the data yields a value of
phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard
Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201
Absolute luminosity measurements with the LHCb detector at the LHC
Absolute luminosity measurements are of general interest for colliding-beam
experiments at storage rings. These measurements are necessary to determine the
absolute cross-sections of reaction processes and are valuable to quantify the
performance of the accelerator. Using data taken in 2010, LHCb has applied two
methods to determine the absolute scale of its luminosity measurements for
proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In
addition to the classic "van der Meer scan" method a novel technique has been
developed which makes use of direct imaging of the individual beams using
beam-gas and beam-beam interactions. This beam imaging method is made possible
by the high resolution of the LHCb vertex detector and the close proximity of
the detector to the beams, and allows beam parameters such as positions, angles
and widths to be determined. The results of the two methods have comparable
precision and are in good agreement. Combining the two methods, an overall
precision of 3.5% in the absolute luminosity determination is reached. The
techniques used to transport the absolute luminosity calibration to the full
2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6,
9 and 10 and corresponding explanation in the tex
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