11,128 research outputs found

    On Multivariate Records from Random Vectors with Independent Components

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    Let X1,X2,…\boldsymbol{X}_1,\boldsymbol{X}_2,\dots be independent copies of a random vector X\boldsymbol{X} with values in Rd\mathbb{R}^d and with a continuous distribution function. The random vector Xn\boldsymbol{X}_n is a complete record, if each of its components is a record. As we require X\boldsymbol{X} to have independent components, crucial results for univariate records clearly carry over. But there are substantial differences as well: While there are infinitely many records in case d=1d=1, there occur only finitely many in the series if d≥2d\geq 2. Consequently, there is a terminal complete record with probability one. We compute the distribution of the random total number of complete records and investigate the distribution of the terminal record. For complete records, the sequence of waiting times forms a Markov chain, but differently from the univariate case, now the state infinity is an absorbing element of the state space

    Some Results on Joint Record Events

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    Let X1,X2,…X_1,X_2,\dots be independent and identically distributed random variables on the real line with a joint continuous distribution function FF. The stochastic behavior of the sequence of subsequent records is well known. Alternatively to that, we investigate the stochastic behavior of arbitrary Xj,Xk,j<kX_j,X_k,j<k, under the condition that they are records, without knowing their orders in the sequence of records. The results are completely different. In particular it turns out that the distribution of XkX_k, being a record, is not affected by the additional knowledge that XjX_j is a record as well. On the contrary, the distribution of XjX_j, being a record, is affected by the additional knowledge that XkX_k is a record as well. If FF has a density, then the gain of this additional information, measured by the corresponding Kullback-Leibler distance, is j/kj/k, independent of FF. We derive the limiting joint distribution of two records, which is not a bivariate extreme value distribution. We extend this result to the case of three records. In a special case we also derive the limiting joint distribution of increments among records

    Omega_{ccc} production via fragmentation at LHC

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    In the framework of the leading order of perturbative QCD and the nonrelativistic quark-diquark model of baryons we have obtained fragmentation function for c-quark to split into Omega_{ccc} baryon. It is shown that at LHC one can expect 3.5 10^3 events with Omega_{ccc} at p_t>5 GeV/c and -1<y<1 per year.Comment: LaTex, 5 pages and 2 figures. Talk presented at XIV Workshop on High Energy Physics and Quantum Field Theory, Moscow, May 27 - June 4, 199

    High-temperature earth-storable propellant acoustic cavity technology

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    Design criteria, methods and data, were developed to permit effective design of acoustic cavities for use in regeneratively cooled OME-type engines. This information was developed experimentally from two series of motor firings with high-temperature fuel during which the engine stability was evaluated under various conditions and with various cavity configurations. Supplementary analyses and acoustic model testing were used to aid cavity design and interpretation of results. Results from this program clearly indicate that dynamic stability in regeneratively cooled OME-type engines can be ensured through the use of acoustic cavities. Moreover, multiple modes of instability were successfully suppressed with the cavity

    Phenomenological Study of Strong Decays of Heavy Hadrons in Heavy Quark Effective Theory

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    The application of the tensor formalism of the heavy quark effective theory (HQET) at leading order to strong decays of heavy hadrons is presented. Comparisons between experimental and theoretical predictions of ratios of decay rates for B mesons, D mesons and kaons are given. The application of HQET to strange mesons presents some encouraging results. The spin-flavor symmetry is used to predict some decay rates that have not yet been measured.Comment: 10 page

    Charge and colour breaking in the constrained MSSM

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    We show that the physical minimum of the Constrained MSSM is only free from dangerous charge and colour breaking minima in the region of parameter space bounded by 110< m_1/2< 400 GeV and 80< m_0< 170 GeV. In the remaining regions, the cosmology is severely constrained

    A relativistic chiral quark model for pseudoscalar emission from heavy mesons

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    The amplitudes for one-pion mediated transitions between heavy meson excited states are obtained in the framework of the relativistic chiral quark model. The effective coupling constants to pions and the decay widths of excited heavy mesons with l<=2 for non-radially excited, and the l=0 radially excited mesons are presented for both charmed and beauty mesons. We also discuss the allowed decays of strange excited heavy mesons by emission of a K-meson.Comment: 20 pages, revte

    More on Symmetries in Heavy Quark Effective Theory

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    We present a general classification of all normal and ``chiral" symmetries of heavy quark effective theories. Some peculiarities and conondrums associated with the ``chiral" symmetries are discussed.Comment: 15 pages, preprint UR-1320, ER40685-77

    Capacity of different cell types to stimulate cytotoxic T lymphocyte precursor cells in the presence of interleukin 2

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    Plastic-adherent cells enriched for dendritic cells (AC) were found to be among the most potent stimulator cells for the activation of cytotoxic T lymphocytes (CTL) in vitro in the presence of interleukin 2 (IL 2) and a constant second set of allogeneic stimulator cells. Concanavalin A-activated nylon wool-nonadherent spleen cells ( CNWT ), concanavalin A-activated unfractionated spleen cells ( Cspl ), and some variants of the ESb T lymphoma line were equally effective as stimulator cells, however, and provoked a substantial cytotoxic response at concentrations of 10(4) cells per culture or less. In contrast, nonactivated nylon wool-nonadherent spleen cells ( NWT ) or unfractionated spleen cells (Spl) and cells of the P815 mastocytoma, the Meth A fibrosarcoma, and the T cell lymphomas Ly 5178 Eb and ESb did not stimulate cytotoxic responses at these cell concentrations. The strong stimulatory potential of the Cspl preparation was reduced by treatment with anti-Thy-1 antibody plus complement, whereas the stimulatory activity of the AC preparation was resistant to this treatment. All cell types tested expressed class I major histocompatibility antigens. Nonactivated NWT cells, in contrast to the CNWT preparation, showed no detectable staining with anti-I-E or anti-I-A antibodies and also a slightly weaker staining with class I antisera. Experiments with the tumor cell lines revealed, however, that there was no strict correlation between stimulatory potential and density of class I alloantigens or the expression of I-E determinants. Experiments on primary cytotoxic responses in vivo gave similar results. Experiments in cultures with a single set of stimulator cells and I region-compatible responder cells indicated that AC and Cspl or CNWT also have a markedly stronger capacity than NWT to induce IL 2-dependent DNA synthesis
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