A generalization of the binary Preparata code

AbstractA classical binary Preparata code P2(m) is a nonlinear (2m+1,22(2m-1-m),6)-code, where m is odd. It has a linear representation over the ring Z4 [Hammons et al., The Z4-linearity of Kerdock, Preparata, Goethals and related codes, IEEE Trans. Inform. Theory 40(2) (1994) 301–319]. Here for any q=2l>2 and any m such that (m,q-1)=1 a nonlinear code Pq(m) over the field F=GF(q) with parameters (q(Δ+1),q2(Δ-m),d⩾3q), where Δ=(qm-1)/(q-1), is constructed. If d=3q this set of parameters generalizes that of P2(m). The equality d=3q is established in the following cases: (1) for a series of initial admissible values q and m such that qm<2100; (2) for m=3,4 and any admissible q, and (3) for admissible q and m such that there exists a number m1 with m1|m and d(Pq(m1))=3q. We apply the approach of [Nechaev and Kuzmin, Linearly presentable codes, Proceedings of the 1996 IEEE International Symposium Information Theory and Application Victoria, BC, Canada 1996, pp. 31–34] the code P is a Reed–Solomon representation of a linear over the Galois ring R=GR(q2,4) code P dual to a linear code K with parameters near to those of generalized linear Kerdock code over R

Accelerating structure of 10 MEV electron linac

The calculation of the on-axis coupled the biperiodic 10 MeV electron accelerating structure is represented. The one-meter structure includes 19 accelerating cells, two of which are bunching cells. Two versions of RF feeding of accelerating structure 2.5 and 4.5 MW are considered. The peak beam current is 0.14 and 0.3 A for these versions. 44…49% of the injected current is accelerated. Shunt impedance is 74 MOhm/m with the 8 mm aperture diameter.Приведено результати розрахунку біперіодичної структури електронного прискорювача на енергію 10 МеВ зі зв'язком по осі. Метрова структура має 19 прискорюючих осередків, два з яких такі, що групують. Розглянуто два варіанти ВЧ-живлення структури потужністю 2,5 і 4,5 МВт. Амплітудне значення струму для цих варіантів дорівнюють 0.14 і 0.3 А, що забезпечує захоплення в процес прискорення 44...49% електронів. Структура з апертурою 8 мм має ефективний шунтовий опір 74 МОм/м.Приведены результаты расчета бипериодической ускоряющей структуры электронного ускорителя на энергию 10 МэВ со связью по оси. Метровая структура имеет 19 ускоряющих ячеек, две из которых группирующие. Рассмотрены два варианта ВЧ-питания ускоряющей структуры мощностью 2,5 и 4,5 МВт. Амплитудные значения тока для этих вариантов равны 0.14 и 0.3 А, что обеспечивает захват в процесс ускорения 44…49% электронов. Структура с апертурой 8 мм имеет эффективное шунтовое сопротивление 74 МОм/м

Giant pulses of pulsar radio emission

Review report of giant pulses of pulsar radio emission, based on our detections of four new pulsars with giant pulses, and the comparative analysis of the previously known pulsars with giant pulses, including the Crab pulsar and millisecond pulsar PSR B1937+21.Comment: Proceedings of the 363. WE-Heraeus Seminar on: Neutron Stars and Pulsars (Posters and contributed talks) Physikzentrum Bad Honnef, Germany, May.14-19, 2006, eds. W.Becker, H.H.Huang, MPE Report 291, pp.72-7

Transfer of synthetic human chromosome into human induced pluripotent stem cells for biomedical applications

Alphoid(tetO)-type human artificial chromosome (HAC) has been recently synthetized as a novel class of gene delivery vectors for induced pluripotent stem cell (iPSC)-based tissue replacement therapeutic approach. This HAC vector was designed to deliver copies of genes into patients with genetic diseases caused by the loss of a particular gene function. The alphoid(tetO)-HAC vector has been successfully transferred into murine embryonic stem cells (ESCs) and maintained stably as an independent chromosome during the proliferation and differentiation of these cells. Human ESCs and iPSCs have significant differences in culturing conditions and pluripotency state in comparison with the murine naïve-type ESCs and iPSCs. To date, transferring alphoid(tetO)-HAC vector into human iPSCs (hiPSCs) remains a challenging task. In this study, we performed the microcell-mediated chromosome transfer (MMCT) of alphoid(tetO)-HAC expressing the green fluorescent protein into newly generated hiPSCs. We used a recently modified MMCT method that employs an envelope protein of amphotropic murine leukemia virus as a targeting cell fusion agent. Our data provide evidence that a totally artificial vector, alphoid(tetO)-HAC, can be transferred and maintained in human iPSCs as an independent autonomous chromosome without affecting pluripotent properties of the cells. These data also open new perspectives for implementing alphoid(tetO)-HAC as a gene therapy tool in future biomedical applications

Measurement of omega meson parameters in pi^+pi^-pi^0 decay mode with CMD-2

About 11 200 e^+e^- -> omega -> pi^+pi^-pi^0 events selected in the center of mass energy range from 760 to 810 MeV were used for the measurement of the \omega meson parameters. The following results have been obtained: sigma _{0}=(1457 \pm 23 \pm 19)nb, m_{\omega}=(782.71 \pm 0.07 \pm 0.04) MeV/c^{2}, \Gamma_{\omega}=(8.68 \pm 0.23 \pm 0.10) MeV, \Gamma_{e^+e^-}\cdot Br (\omega -> pi^+pi^-pi^0)= (0.528 \pm 0.012 \pm 0.007) \cdot 10^{-3} MeV.Comment: 8 pages, 4 figure

Cross section of the reaction e+e−→π+π−π+π−e^+ e^- \to \pi^+\pi^-\pi^+\pi^- below 1 GeV at CMD-2

Using 3.07 ${pb}^{-1}$ of data collected in the energy range 0.60-0.97 GeV by CMD-2, about 150 events of the process \epm \to \pch have been selected. The energy dependence of the cross section agrees with the assumption of the $a_1(1260) \pi$ intermediate state which is dominant above 1 GeV. For the first time \fourpi events are observed at the $\rho$ meson energy. Under the assumption that all these events come from the $\rho$ meson decay, the value of the cross section at the $\rho$ meson peak corresponds to the following decay width: \Gamma(\rho^0 \to \fourpi) = (2.8 \pm 1.4 \pm 0.5) {keV} or to the branching ratio B(\rho^0 \to \fourpi) = (1.8 \pm 0.9 \pm 0.3) \cdot 10 ^{-5}.Comment: 15 pages, 5 figure

Study of the process e+e- to pi+pi-pi+pi-pi0 with CMD-2 detector

The process e+e- to pi+ pi- pi+ pi- pi0 has been studied in the center of mass energy range 1280 -- 1380 MeV using 3.0 1/pb of data collected with the CMD-2 detector in Novosibirsk. Analysis shows that the cross section of the five pion production is dominated by the contributions of the eta pi+pi- and omega pi+pi- intermediate states.Comment: 8 pages, 3 figure. Submitted to Phys. Lett.

Neutrino Quasielastic Scattering on Nuclear Targets: Parametrizing Transverse Enhancement (Meson Exchange Currents)

We present a parametrization of the observed enhancement in the transverse electron quasielastic (QE) response function for nucleons bound in carbon as a function of the square of the four momentum transfer ($Q^2$) in terms of a correction to the magnetic form factors of bound nucleons. The parametrization should also be applicable to the transverse cross section in neutrino scattering. If the transverse enhancement originates from meson exchange currents (MEC), then it is theoretically expected that any enhancement in the longitudinal or axial contributions is small. We present the predictions of the "Transverse Enhancement" model (which is based on electron scattering data only) for the $\nu_\mu, \bar{\nu}_\mu$ differential and total QE cross sections for nucleons bound in carbon. The $Q^2$ dependence of the transverse enhancement is observed to resolve much of the long standing discrepancy in the QE total cross sections and differential distributions between low energy and high energy neutrino experiments on nuclear targets.Comment: Revised Version- July 21, 2011: 17 pages, 20 Figures. To be published in Eur. Phys. J.

The Seven-sphere and its Kac-Moody Algebra

We investigate the seven-sphere as a group-like manifold and its extension to a Kac-Moody-like algebra. Covariance properties and tensorial composition of spinors under $S^7$ are defined. The relation to Malcev algebras is established. The consequences for octonionic projective spaces are examined. Current algebras are formulated and their anomalies are derived, and shown to be unique (even regarding numerical coefficients) up to redefinitions of the currents. Nilpotency of the BRST operator is consistent with one particular expression in the class of (field-dependent) anomalies. A Sugawara construction is given.Comment: 22 pages. Macropackages used: phyzzx, epsf. Three epsf figure files appende

Measurement of ϕ\phi(1020) meson leptonic width with CMD-2 detector at VEPP-2M Collider

The $\phi$(1020) meson leptonic width has been determined from the combined analysis of 4 major decay modes of the resonance ($\phi\to K^+ K^-,K^0_LK^0_S,\pi^+\pi^-\pi^0,\eta\gamma$) studied with the CMD-2 detector at the VEPP-2M $e^+e^-$ collider. The following value has been obtained: $\Gamma(\phi\to e^+e^-) = 1.235\pm 0.006\pm 0.022$ keV. The $\phi(1020)$ meson parameters in four main decay channels have been also recalculated: $B(\phi\to K^+K^-) = 0.493\pm 0.003\pm 0.007$, $B(\phi\to K_LK_S) = 0.336\pm 0.002\pm 0.006$, $B(\phi\to\pi^+\pi^-\pi^0) = 0.155\pm 0.002\pm 0.005$, $B(\phi\to\eta\gamma) = 0.0138\pm 0.0002\pm 0.0002$.Comment: 14 pages, 3 figure