On Sp(2M) Invariant Green Functions

Explicit form of two-point and three-point Sp(2M) invariant Green functions is found.Comment: 7 page

Alfven Wave Generation by means of High Orbital Injection of Barium Cloud in Magnetosphere

An analysis of the Alfven wave generation associated with the barium vapor release at altitudes ~ 5.2 Earth's radii (ER) in the magnetosphere is presented. Such injections were executed in G-8 and G-10 experiments of the Combined Radiation and Radiation Effects Satellite (CRRES) mission. It is shown that the generation of Alfven waves is possible during the total time of plasma expansion. The maximum intensity of these waves corresponds to the time of complete retardation of the diamagnetic cavity created by the expansion of plasma cloud. The Alfven wave exhibits a form of an impulse with an effective frequency ~ 0.03-0.05 Hz. Due to the background conditions and wave frequency, the wave mainly oscillates along the geomagnetic field between the mirror reflection points situated at ~ 0.7 ER. The wave amplitude is sufficient to the generation of plasma instabilities and longitudinal electric field, and to an increase in the longitudinal energy of electrons to ~ 1 keV. These processes are the most probable for altitudes ~ 1 ER. The auroral kilometric radiation (AKR) at frequencies ~ 100 kHz is associated with these accelerated electrons. The acceleration of electrons and AKR can be observed almost continuously during the first minute and then from time to time with pauses about 35-40 s till 6-8 min after the release. The betatron acceleration of electrons at the recovery of the geomagnetic field is also discussed. This mechanism could be responsible for the acceleration of electrons resulting in the aurorae and ultra short radio wave storm at frequencies 50-300 MHz observed at the 8-10th min after the release.Comment: Presented at COSPAR 200

Structure of TiAlN Reactive Sputtered Coatings

The Raman spectra, X-ray diffraction and hardness of the TiAlN films co-deposited on the steel substrates by reactive sputtering from Ti and Al targets in a mixture of N2 + Ar gas with two magnetrons at room temperature have been studied. From Raman spectra it is found that the position of high-frequency bands in vibrational spectra was located at 700-730 cm 1 or in the region of 830 850 cm 1 depending on the deposition parameters whereas it is not exceed 630 cm 1 from TiAlN of NaCl structure. It is found the two-phase structure of coatings: a small quantity of NaCl-type structure of TiAlN (TiN) and the disordered structure of the chains of polyhedra [TiNx] with x = 5 and x = 4. The chains of polyhedra [TiNx] with x = 4 are mainly formed at large discharge power of Al(Ti) target or at small content of N2 gas. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2492

A next-to-leading order analysis of deeply virtual Compton scattering

We present a complete, next-to-leading-order (NLO), leading-twist QCD analysis of deeply virtual Compton scattering (DVCS) observables, in the ${\bar {MS}}$ scheme, and in the kinematic ranges of the H1, ZEUS and HERMES experiments. We use a modified form of Radyushkin's ansatz for the input model for the generalized parton distributions. We present results for leading order (LO) and NLO for representative observables and find that they compare favourably to the available data.Comment: 5 pages, 2 figures, revtex, published version, we modify Radyushkin's ansatz for the GPDs to correct for finite hadronic mass effects, and, using the latest MRST PDFs, now agree with the H1 data (modified figs). Typo in Eq.(3) correcte

Extraction of Kaon Formfactors from K^- -> mu^- nu_mu gamma Decay at ISTRA+ Setup

The radiative decay K->mu nu gamma has been studied at ISTRA+ setup in a new kinematical region. About 22K events of K^- -> mu^- nu_mu gamma have been observed. The sign and value of Fv-Fa have been measured for the first time. The result is Fv-Fa=0.21(4)(4).Comment: 11 pages, 21 figures, submitted to Phys. Lett.

Search for light pseudoscalar sgoldstino in K- decays

A search for the light pseudoscalar sgoldstino production in the three body K- decay K-->pipi0P has been performed with the ISTRA+ detector exposed to the 25 GeV negative secondary beam of the U70 proton synchrotron. No signal is seen. An upper limit for the branching ratio Br(K->pipi0P), at 90% confidence level, is found to be around 9*10**-6 in the effective mass m(P) range from 0 till 200 MeV, excluding the region near m(pi0) where it degrades to 3.5*10**-5.Comment: 10 pages, LATEX, 8 EPS figures, revised version, to be published in Phys.Lett.

High statistic measurement of the K- -> pi0 e- nu decay form-factors

The decay K- -> pi0 e- nu is studied using in-flight decays detected with the ISTRA+ spectrometer. About 920K events are collected for the analysis. The lambda+ slope parameter of the decay form-factor f+(t) in the linear approximation (average slope) is measured: lambda+(lin)= 0.02774 +- 0.00047(stat) +- 0.00032(syst). The quadratic contribution to the form-factor was estimated to be lambda'+ = 0.00084 +- 0.00027(stat) +- 0.00031(syst). The linear slope, which has a meaning of df+(t)/dt|_{t=0} for this fit, is lambda+ = 0.02324 +- 0.00152(stat) +- 0.00032(syst). The limits on possible tensor and scalar couplings are derived: f_{T}/f_{+}(0)=-0.012 +- 0.021(stat) +- 0.011$(syst), f_{S}/f_{+}(0)=-0.0037^{+0.0066}_{-0.0056}(stat) +- 0.0041(syst).Comment: 11 pages, 8 figures. Accepted by Phys.Lett.

A next-to-leading order QCD analysis of deeply virtual Compton scattering amplitudes

We present a next-to-leading order (NLO) QCD analysis of unpolarized and polarized deeply virtual Compton scattering (DVCS) amplitudes, for two different input scenarios, in the $\bar{MS}$ scheme. We illustrate and discuss the size of the NLO effects and the behavior of the amplitudes in skewedness, $\zeta$, and photon virtuality, $Q^2$. In the unpolarized case, at fixed $Q^2$, we find a remarkable effective power-law behaviour in $\zeta$, akin to Regge factorization, over several orders of magnitude in $\zeta$. We also quantify the ratio of real to imaginary parts of the DVCS amplitudes and their sensitivity to changes of the factorization scale.Comment: 12 pages, 12 figures, revtex, final version to be published in Phys. Rev. D. Corrected error in MRSA' distribution and modified extraplation behavior of GRSV00 distribution. Corrected error in +i\epsilon treatment. Taking now correct sheaf of log. Errors in subtraction equations corrected. Figures and results for affected imaginary part of NLO amplitude changed accordingl

Search for Heavy Neutrino in K->mu nu_h(nu_h-> nu gamma) Decay at ISTRA+ Setup

Heavy neutrino nu_h with m_h < 300MeV/c^2 can be effectively searched for in kaon decays. We put upper limits on mixing matrix element |U_mu_h}|^2 for radiatively decaying nu_h from K->mu nu_h (nu_h -> nu gamma) decay chain in the following parameter region: 30MeV/c^2 < m_h < 80MeV/c^2; 10^{-11}sec < tau_h < 10^{-9}sec. For the whole region |U_{mu h}|^2 < 5 x 10^{-5} for Majorana type of nu_h and | U_{\mu h}|^2 < 8 x 10^{-5} for the Dirac case.Comment: Published in Phys. Lett.