1,924 research outputs found

    Calibrating the Na\"ive Cornell Model with NRQCD

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    Along the years, the Cornell Model has been extraordinarily successful in describing hadronic phenomenology, in particular in physical situations for which an effective theory of the strong interactions such as NRQCD cannot be applied. As a consequence of its achievements, a relevant question is whether its model parameters can somehow be related to fundamental constants of QCD. We shall give a first answer in this article by comparing the predictions of both approaches. Building on results from a previous study on heavy meson spectroscopy, we calibrate the Cornell model employing NRQCD predictions for the lowest-lying bottomonium states up to N3^3LO, in which the bottom mass is varied within a wide range. We find that the Cornell model mass parameter can be identified, within perturbative uncertainties, with the MSR mass at the scale R=1 R = 1\,GeV. This identification holds for any value of αs\alpha_s or the bottom mass, and for all perturbative orders investigated. Furthermore, we show that: a) the "string tension" parameter is independent of the bottom mass, and b) the Coulomb strength κ\kappa of the Cornell model can be related to the QCD strong coupling constant αs\alpha_s at a characteristic non-relativistic scale. We also show how to remove the u=1/2u=1/2 renormalon of the static QCD potential and sum-up large logs related to the renormalon subtraction by switching to the low-scale, short-distance MSR mass, and using R-evolution. Our R-improved expression for the static potential remains independent of the heavy quark mass value and agrees with lattice QCD results for values of the radius as large as 0.8 0.8\,fm, and with the Cornell model potential at long distances. Finally we show that for moderate values of rr, the R-improved NRQCD and Cornell static potentials are in head-on agreement.Comment: 22 pages, 13 figures, 3 table

    Puzzles in quarkonium hadronic transitions with two pion emission

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    The anomalously large rates of some hadronic transitions from quarkonium are studied using QCD multipole expansion (QCDME) in the framework of a constituent quark model which has been successful in describing hadronic phenomenology. The hybrid intermediate states needed in the QCDME method are calculated in a natural extension of our constituent quark model based on the Quark Confining String (QCS) scheme. Some of the anomalies are explained due to the presence of an hybrid state with a mass near the mass of the decaying resonance whereas other are justified by the presence of molecular components in the wave function. Some unexpected results are pointed out.Comment: Conference proceedings of the XI Quark Confinement and the Hadron Spectrum (CONFINEMENT XI). Saint Petersburg (Russia) from 8 to 12 September 201

    Molecular components in P-wave charmed-strange mesons

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    Results obtained by various experiments show that the Ds0∗(2317)D_{s0}^{\ast}(2317) and Ds1(2460)D_{s1}(2460) mesons are very narrow states located below the DKDK and D∗KD^{\ast}K thresholds, respectively. This is markedly in contrast with the expectations of naive quark models and heavy quark symmetry. Motivated by a recent lattice study which addresses the mass shifts of the csˉc\bar{s} ground states with quantum numbers JP=0+J^{P}=0^{+} (Ds0∗(2317)D_{s0}^{\ast}(2317)) and JP=1+J^{P}=1^{+} (Ds1(2460)D_{s1}(2460)) due to their coupling with SS-wave D(∗)KD^{(\ast)}K thresholds, we perform a similar analysis within a nonrelativistic constituent quark model in which quark-antiquark and meson-meson degrees of freedom are incorporated. The quark model has been applied to a wide range of hadronic observables and thus the model parameters are completely constrained. The coupling between quark-antiquark and meson-meson Fock components is done using a 3P0^{3}P_{0} model in which its only free parameter γ\gamma has been elucidated performing a global fit to the decay widths of mesons that belong to different quark sectors, from light to heavy. We observe that the coupling of the 0+0^{+} (1+)(1^{+}) meson sector to the DKDK (D∗K)(D^{\ast}K) threshold is the key feature to simultaneously lower the masses of the corresponding Ds0∗(2317)D_{s0}^{\ast}(2317) and Ds1(2460)D_{s1}(2460) states predicted by the naive quark model and describe the Ds1(2536)D_{s1}(2536) meson as the 1+1^{+} state of the jqP=3/2+j_{q}^{P}=3/2^{+} doublet predicted by heavy quark symmetry, reproducing its strong decay properties. Our calculation allows to introduce the coupling with the DD-wave D∗KD^{\ast}K channel and the computation of the probabilities associated with the different Fock components of the physical state.Comment: 11 pages, 3 figures, 7 table

    In-vitro experiment of Listeria reduction in ready-to-eat dry cured sausages

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    The risk of listeriosis associated with ready-to-eat foods is a major concern in United States. The recently published United States regulations require ready-to-eat meat producers to control Listeria monocytogenes, using interventions which may include antimicrobials that reduce post-processing contamination by at least 1 log cycle and that no more than 1 log increase throughout product shelf life. This regulation impact also the Spanish meat producers especially dry cured sausages, which export their products to USA. In this study, we analyzed in vitro, individually and in combinations, the commonly applied antimicrobials to reduce Listeria. Performing in-vitro experiment before applying directly on dry cured sausages offer us the benefits such as time and cost saving
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