9,706 research outputs found

    Effect of the ηη\eta\eta channel and interference phenomena in the two-pion transitions of charmonia and bottomonia

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    The basic shape of di-pion mass spectra in the two-pion transitions of both charmonia and bottomonia states is explained by an unified mechanism based on contributions of the ππ\pi\pi, KKK\overline{K} and ηη\eta\eta coupled channels including their interference. The role of the individual f0f_0 resonances in shaping the di-pion mass distributions in the charmonia and bottomonia decays is considered.Comment: 8 pages, 4 figures, Talk at the XXIII International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics \& Quantum Chromodynamics" (Dubna, Russia, 19--24 September 2016). arXiv admin note: text overlap with arXiv:1610.0789

    The interference effects of multi-channel pion-pion scattering contributions to the final states of Ψ\Psi- and Υ\Upsilon-meson family decays

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    It is shown that the basic shape of dipion mass distributions in the two-pion transitions of both charmonia and bottomonia states are explained by an unified mechanism based on the contribution of the ππ\pi\pi, KKK\overline{K} and ηη\eta\eta coupled channels including their interference.Comment: 5 pages, 3 figures, talk at the14th International Workshop on Meson Production, Properties and Interaction (Krakow, Poland, 2nd - 7th June 2016

    C2_2H observations toward the Orion Bar

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    C2_2H is one of the first radicals to be detected in the interstellar medium. Its higher rotational transitions have recently become available with the Herschel Space Observatory. We aim to constrain the physical parameters of the C2_2H emitting gas toward the Orion Bar. We analyse the C2_2H line intensities measured toward the Orion Bar CO+^+ Peak and Herschel/HIFI maps of C2_2H, CH, and HCO+^+, and a NANTEN map of [CI]. We interpret the observed C2_2H emission using radiative transfer and PDR models. Five rotational transitions of C2_2H have been detected in the HIFI frequency range toward the CO+^+ peak. A single component rotational diagram gives a rotation temperature of ~64 K and a beam-averaged C2_2H column density of 4×\times1013^{13} cm2^{-2}. The measured transitions cannot be explained by any single parameter model. According to a non-LTE model, most of the C2_2H column density produces the lower-NN C2_2H transitions and traces a warm (TkinT_{\rm{kin}} ~ 100-150 K) and dense (nn(H2_2)~105^5-106^6 cm3^{-3}) gas. A small fraction of the C2_2H column density is required to reproduce the intensity of the highest-NN transitions (NN=9-8 and N=10-9) originating from a high density (nn(H2_2)~5×\times106^6 cm3^{-3}) hot (TkinT_{\rm{kin}} ~ 400 K) gas. The total beam-averaged C2_2H column density in the model is 1014^{14} cm2^{-2}. Both the non-LTE radiative transfer model and a simple PDR model representing the Orion Bar with a plane-parallel slab of gas and dust suggest, that C2_2H cannot be described by a single pressure component, unlike the reactive ion CH+^+, which was previously analysed toward the Orion Bar CO+^+ peak. The physical parameters traced by the higher rotational transitions (NN=6-5,...,10-9) of C2_2H may be consistent with the edges of dense clumps exposed to UV radiation near the ionization front of the Orion Bar.Comment: Proposed for acceptance in A&A, abstract abridge

    Parametrization of semi-dynamical quantum reflection algebra

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    We construct sets of structure matrices for the semi-dynamical reflection algebra, solving the Yang-Baxter type consistency equations extended by the action of an automorphism of the auxiliary space. These solutions are parametrized by dynamical conjugation matrices, Drinfel'd twist representations and quantum non-dynamical RR-matrices. They yield factorized forms for the monodromy matrices.Comment: LaTeX, 24 pages. Misprints corrected, comments added in Conclusion on construction of Hamiltonian

    Are Simple Real Pole Solutions Physical?

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    We consider exact solutions generated by the inverse scattering technique, also known as the soliton transformation. In particular, we study the class of simple real pole solutions. For quite some time, those solutions have been considered interesting as models of cosmological shock waves. A coordinate singularity on the wave fronts was removed by a transformation which induces a null fluid with negative energy density on the wave front. This null fluid is usually seen as another coordinate artifact, since there seems to be a general belief that that this kind of solution can be seen as the real pole limit of the smooth solution generated with a pair of complex conjugate poles in the transformation. We perform this limit explicitly, and find that the belief is unfounded: two coalescing complex conjugate poles cannot yield a solution with one real pole. Instead, the two complex conjugate poles go to a different limit, what we call a ``pole on a pole''. The limiting procedure is not unique; it is sensitive to how quickly some parameters approach zero. We also show that there exists no improved coordinate transformation which would remove the negative energy density. We conclude that negative energy is an intrinsic part of this class of solutions.Comment: 13 pages, 3 figure

    Implementation status of mandatory inspection of sprayers in Romania

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    To harmonize the Romanian legislation on plant protection to the European legislation the Directive 128/2009 has been transposed into national legislation by Government Emergency Ordinance 34/2012 on establishing the institutional framework for action to the sustainable use of pesticides in Romania.National Action Plan approved by Decision 683/2013, on reducing the risks associated with the use of plant protection products is the strategic document regarding the continuous improvement of the use of plant protection products and contains quantitative targets, measures and timetables to reduce risks and the effects of using plant protection products on the environment and human health
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