1,781 research outputs found

    Ωc\Omega_c excited states: a molecular approach with heavy-quark spin symmetry

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    The LHCb Collaboration has recently discovered five excited Ωc\Omega_c states with masses between 3 and 3.1 GeV, four of them corroborated by the Belle Collaboration. We analyse the dynamical generation of these states within a molecular baryon-meson model that is consistent with both chiral and heavy-quark spin symmetries. Earlier predictions within this model found five Ωc\Omega_c states with masses below 3 GeV. Thus, in order to study the possible identification of any of these states with the experimental ones in the correct energy region, we explore two different regularization schemes, that is, a modified regularization subtraction method and a cutoff regularization scheme. We find that at least three of the dynamically generated states can be identified with the experimental ones and have spin-parity J=1/2J=1/2^- or J=3/2J=3/2^-Comment: 6 pages, 3 tables, 1 figure, contribution based on a keynote parallel talk of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), November 13-17, 2018, Tsukuba (Japan

    Ωc\Omega_c excited states within a SU(6)lsf×{\rm SU(6)}_{\rm lsf}\timesHQSS model

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    We have reviewed the renormalization procedure used in the unitarized coupled-channel model of Phys. Rev. D85 114032 (2012), and its impact in the C=1C=1, S=2S=-2, and I=0I=0 sector, where five Ωc()\Omega_c^{(*)} states have been recently observed by the LHCb Collaboration. The meson-baryon interactions used in the model are consistent with both chiral and heavy-quark spin symmetries and lead to a successful description of the observed lowest-lying odd parity resonances Λc(2595)\Lambda_c(2595) and Λc(2625)\Lambda_c(2625), and Λb(5912)\Lambda_b(5912) and Λb(5920)\Lambda_b(5920) resonances. We show that some (probably at least three) of the states observed by LHCb will also have odd parity and spins J=1/2J=1/2 and J=3/2J=3/2, belonging two of them to the same SU(6)lightspinflavor×{\rm SU(6)}_{\rm light-spin-flavor}\timesHQSS multiplets that the latter strangenessless heavyΛ-\Lambda baryons.Comment: 11 pages, 3 figures, 6 tables, published in The European Physical Journal

    Scratching the Surface and Digging Deeper: Exploring Ecological Theories in Urban Soils

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    Humans have altered the Earth more extensively during the past 50 years than at any other time in history (Millennium Assessment 2003). A significant part of this global change is the conversion of land covers from native ecosystems to those dominated by human activities (Kareiva et al. 2007; Ellis and Ramankutty 2008). Although agricultural needs have historicall

    Unfoldings of saddle-nodes and their Dulac time

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    In this paper we study unfoldings of saddle-nodes and their Dulac time. By unfolding a saddle-node, saddles and nodes appear. In the first result (Theorem A) we prove uniform regularity by which orbits and their derivatives arrive at a node. Uniformity is with respect to all parameters including the unfolding parameter bringing the node to a saddle-node and a parameter belonging to a space of functions. In the second part, we apply this first result for proving a regularity result (Theorem B) on the Dulac time (time of Dulac map) of an unfolding of a saddle-node. This result is a building block in the study of bifurcations of critical periods in a neighbourhood of a polycycle. Finally, we apply Theorems A and B to the study of critical periods of the Loud family of quadratic centers and we prove that no bifurcation occurs for certain values of the parameters (Theorem C)

    INVESTIGATING THE POWER IN FREIGHT TRANSPORT COMMUNICATION NETWORK STRUCTURE

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    The business of freight transportation is undergoing a technological revolution at it moves toward the 21st century. New technologies are being developed and adopted in each mode of freight transportation. The one technology that affects all modes is information technology. Information technology related to the coordination of logistics and supply chain management, has the capability of affecting all the modes in a similar way. This technology in the form of electronic data interchange has begun to automate, and reduce the costs of, paper flow required to move goods from shippers, through carriers and transfer points, to consignees. Surveys of the freight transportation industry indicate that the adoption of EDI has not been nearly universal in any dimension. The paper investigates the structure of the communication system used for transport supply chain.POWER electronic commerce freight transport network structure
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