392 research outputs found

    Towards unified theory of 2d2d gravity

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    We introduce a new 1-matrix model with arbitrary potential and the matrix-valued background field. Its partition function is a τ\tau-function of KP-hierarchy, subjected to a kind of L1{\cal L}_{-1}-constraint. Moreover, partition function behaves smoothly in the limit of infinitely large matrices. If the potential is equal to XK+1X^{K+1}, this partition function becomes a τ\tau-function of KK-reduced KP-hierarchy, obeying a set of WK{\cal W} _K-algebra constraints identical to those conjectured in \cite{FKN91} for double-scaling continuum limit of (K1)(K-1)-matrix model. In the case of K=2K=2 the statement reduces to the early established \cite{MMM91b} relation between Kontsevich model and the ordinary 2d2d quantum gravity . Kontsevich model with generic potential may be considered as interpolation between all the models of 2d2d quantum gravity with c<1c<1 preserving the property of integrability and the analogue of string equation.Comment: 67 pages (October 1991

    An hbar-expansion of the Toda hierarchy: a recursive construction of solutions

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    A construction of general solutions of the \hbar-dependent Toda hierarchy is presented. The construction is based on a Riemann-Hilbert problem for the pairs (L,M) and (\bar L,\bar M) of Lax and Orlov-Schulman operators. This Riemann-Hilbert problem is translated to the language of the dressing operators W and \bar W. The dressing operators are set in an exponential form as W = e^{X/\hbar} and \bar W = e^{\phi/\hbar}e^{\bar X/\hbar}, and the auxiliary operators X,\bar X and the function \phi are assumed to have \hbar-expansions X = X_0 + \hbar X_1 + ..., \bar X = \bar X_0 + \hbar\bar X_1 + ... and \phi = \phi_0 + \hbar\phi_1 + .... The coefficients of these expansions turn out to satisfy a set of recursion relations. X,\bar X and \phi are recursively determined by these relations. Moreover, the associated wave functions are shown to have the WKB form \Psi = e^{S/\hbar} and \bar\Psi = e^{\bar S/\hbar}, which leads to an \hbar-expansion of the logarithm of the tau function.Comment: 37 pages, no figures. arXiv admin note: substantial text overlap with arXiv:0912.486

    Additional symmetries of constrained CKP and BKP hierarchies

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    The additional symmetries of the constrained CKP (cCKP) and BKP (cBKP) hierarchies are given by their actions on the Lax operators, and their actions on the eigenfunction and adjoint eigenfunction {Φi,Ψi}\{\Phi_i,\Psi_i \} are presented explicitly. Furthermore, we show that acting on the space of the wave operator, k\partial_k^* forms new centerless W1+cCW^{cC}_{1+\infty} and W1+cBW^{cB}_{1+\infty}-subalgebra of centerless W1+W_{1+\infty} respectively. In order to define above symmetry flows k\partial_k^* of the cCKP and cBKP hierarchies, two vital operators YkY_k are introduced to revise the additional symmetry flows of the CKP and BKP hierarchies.Comment: 14 pages, accepted by SCIENCE CHINA Mathematics(2010

    Measurement of J/ψγηcJ/\psi\to\gamma\eta_{\rm c} decay rate and ηc\eta_{\rm c} parameters at KEDR

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    Using the inclusive photon spectrum based on a data sample collected at the J/ψJ/\psi peak with the KEDR detector at the VEPP-4M e+ee^+e^- collider, we measured the rate of the radiative decay J/ψγηcJ/\psi\to\gamma\eta_{\rm c} as well as ηc\eta_{\rm c} mass and width. Taking into account an asymmetric photon lineshape we obtained Γγηc0=2.98±0.180.33+0.15\Gamma^0_{\gamma\eta_{\rm c}}=2.98\pm0.18 \phantom{|}^{+0.15}_{-0.33} keV, Mηc=2983.5±1.43.6+1.6M_{\eta_{\rm c}} = 2983.5 \pm 1.4 \phantom{|}^{+1.6}_{-3.6} MeV/c2c^2, Γηc=27.2±3.12.6+5.4\Gamma_{\eta_{\rm c}} = 27.2 \pm 3.1 \phantom{|}^{+5.4}_{-2.6} MeV.Comment: 6 pages, 3 figure

    К ВЫБОРУ ИСТОЧНИКА ТЕПЛОСНАБЖЕНИЯ МОБИЛЬНОГО СТРОИТЕЛЬНОГО СООРУЖЕНИЯ

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    The paper proposes a vortex heat generator with energy transformation of the highest  state  of matter motion  into  the  lowest  one  as  a  heat  supply  source  for a mobile object. Energy transformation coefficient indices close or equal to 1 have been obtained as a result of experiments on efficiency of the vortex heat generator. Such results can be explained with the help of the 2nd Bohr quantum postulate. Standard series of certified VTG heat generators has been proposed for heat supply of the mobile object (field hospital).В качестве источника теплоснабжения мобильного  объекта предложенвихревой теплогенератор с преобразованием энергии высшей формы движения материи в низшую. В ходе опытов по определению эффективности вихревого теплогенератора были получены значения коэффициента преобразования энергии, близкие и равные единице. Такие результаты могут быть объяснены с помощью второго квантового постулата Бора. Для теплоснабжения мобильного объекта (полевого госпиталя) предложен типоряд сертифицированных теплогенераторов марки ВТГ

    Measurement of J/psi to eta_c gamma at KEDR

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    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, Chin

    Measurement of B(J/psi->eta_c gamma) at KEDR

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    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, Beijin
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