11,243 research outputs found

    Production of scalar KKˉK\bar K molecules in ϕ\phi radiative decays

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    The potentialities of the production of the scalar KKˉK\bar K molecules in the ϕ\phi radiative decays are considered beyond the narrow resonance width approximation. It is shown that $BR(\phi\rightarrow\gamma f_0(a_0)\rightarrow\gamma\pi\pi(\pi\eta))\approx (1\div 2)\times 10^{-5}\ ,\BR(\phi\rightarrow\gamma (f_0+a_0)\rightarrow\gamma K^+K^-)\alt 10^{-6}and and BR(\phi\rightarrow\gamma (f_0+a_0) \to \gamma K^0\bar K^0)\alt 10^{-8}.Themassspectrainthe. The mass spectra in the \pi\pi\ ,\ \pi\eta\ ,\ K^+K^-\ ,\ K^0\bar K^0channelsarecalculated.Theimaginarypartoftheamplitude channels are calculated. The imaginary part of the amplitude \phi\rightarrow\gamma f_0(a_0)iscalculatedanalytically.Itisobtainedthephaseofthescalarresonanceproductionamplitudethatcausestheinterferencepatternsinthereaction is calculated analytically. It is obtained the phase of the scalar resonance production amplitude that causes the interference patterns in the reaction e^+e^-\rightarrow\gamma \pi^+\pi^-inthe in the \phi$ meson mass region.Comment: 19 pages, revtex, 4 eps files of figure

    An effectual template bank for the detection of gravitational waves from inspiralling compact binaries with generic spins

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    We report the construction of a three-dimensional template bank for the search for gravitational waves from inspiralling binaries consisting of spinning compact objects. The parameter space consists of two dimensions describing the mass parameters and one "reduced-spin" parameter, which describes the secular (non-precessing) spin effects in the waveform. The template placement is based on an efficient stochastic algorithm and makes use of the semi-analytical computation of a metric in the parameter space. We demonstrate that for "low-mass" (m1+m2≲12 M⊙m_1 + m_2 \lesssim 12\,M_\odot) binaries, this template bank achieves effective fitting factors ∼0.92\sim0.92--0.990.99 towards signals from generic spinning binaries in the advanced detector era over the entire parameter space of interest (including binary neutron stars, binary black holes, and black hole-neutron star binaries). This provides a powerful and viable method for searching for gravitational waves from generic spinning low-mass compact binaries. Under the assumption that spin magnitudes of black-holes [neutron-stars] are uniformly distributed between 0--0.98 [0 -- 0.4] and spin angles are isotropically distributed, the expected improvement in the average detection volume (at a fixed signal-to-noise-ratio threshold) of a search using this reduced-spin bank is ∼20−52%\sim20-52\%, as compared to a search using a non-spinning bank.Comment: Minor changes, version appeared in Phys. Rev.

    Four-quark state in QCD

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    The spectra of some 0++ four-quark states, which are composed of \bar qq pairs, are calculated in QCD. The light four-quark states are calculated using the traditional sum rules while four-quark states containing one heavy quark are computed in HQET. For constructing the interpolating currents, different couplings of the color and spin inside the \bar qq pair are taken into account. It is found that the spin and color combination has little effect on the mass of the four-quark states.Comment: 10 pages, 4 ps figures, Late

    Geometric quantization of Hamiltonian actions of Lie algebroids and Lie groupoids

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    We construct Hermitian representations of Lie algebroids and associated unitary representations of Lie groupoids by a geometric quantization procedure. For this purpose we introduce a new notion of Hamiltonian Lie algebroid actions. The first step of our procedure consists of the construction of a prequantization line bundle. Next, we discuss a version of K\"{a}hler quantization suitable for this setting. We proceed by defining a Marsden-Weinstein quotient for our setting and prove a ``quantization commutes with reduction'' theorem. We explain how our geometric quantization procedure relates to a possible orbit method for Lie groupoids. Our theory encompasses the geometric quantization of symplectic manifolds, Hamiltonian Lie algebra actions, actions of families of Lie groups, foliations, as well as some general constructions from differential geometry.Comment: 40 pages, corrected version 11-01-200

    On Deusons or Deuteronlike Meson-Meson Bound States

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    The systematics of deuteronlike two-meson bound states, {\it deusons}, is discussed. Previous arguments that many of the present non-qqˉq\bar q states are such states are elaborated including, in particular, the tensor potential. For pseudoscalar states the important observation is made that the centrifugal barrier from the P-wave can be overcome by the 1/r21/r^2 and 1/r31/r^3 terms of the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like BBˉ∗B\bar B^* and B∗Bˉ∗B^*\bar B^* composites bound by approximately 50 MeV, while DDˉ∗D\bar D^* and D∗Dˉ∗D^*\bar D^* states are expected near the threshold.Comment: Invited talk at the Hadron93 International Conf. on Hadron Spectroscopy, Como, Italy 22.-25.6. 1993. 5 pages in LATEX HU-SEFT R 1993-13

    Vibrational energy transfer in ultracold molecule - molecule collisions

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    We present a rigorous study of vibrational relaxation in p-H2 + p-H2 collisions at cold and ultracold temperatures and identify an efficient mechanism of ro-vibrational energy transfer. If the colliding molecules are in different rotational and vibrational levels, the internal energy may be transferred between the molecules through an extremely state-selective process involving simultaneous conservation of internal energy and total rotational angular momentum. The same transition in collisions of distinguishable molecules corresponds to the rotational energy transfer from one vibrational state of the colliding molecules to another.Comment: 4 pages, 4 figure

    Research on solar pumped liquid lasers

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    A solar pumped liquid laser that can be scaled up to high power (10Mw CW) for space applications was developed. Liquid lasers have the inherent advantage over gases in that they provide much higher lasant densities and thus high power densities. Liquids also have inherent advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13:Nd(3+):ZrC14 liquid was chosen for its high intrinsic efficiency as well as its relatively good stability against decomposition due to protic contamination. The development and testing of the laser liquid and the development of a large solar concentrator to pump the laser was emphasized. The procedure to manufacture the laser liquid must include diagnostic tests of the solvent purity (from protic contamination) at various stages in the production process

    Research on solar pumped liquid lasers

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    A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined

    Task iv- /research/ of the solar energy thermionic /set/ conversion development program third quarterly progress report, 1 dec. 1964 - 28 feb. 1965

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    Operational parameters for thermionic converter - cesium vapor diode formulation and computer method of analysi
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