163 research outputs found

    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)light−spin−flavor×{\rm SU(6)}_{\rm light-spin-flavor}\timesHQSS multiplets that the latter strangenessless heavy−Λ-\Lambda baryons.Comment: 11 pages, 3 figures, 6 tables, published in The European Physical Journal

    Coupled channels dynamics in the generation of the Ω(2012)\Omega (2012) resonance

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    We look into the newly observed Ω(2012)\Omega (2012) state from the molecular perspective in which the resonance is generated from the KˉΞ∗\bar{K} \Xi^*, ηΩ\eta \Omega and KˉΞ\bar{K} \Xi channels. We find that this picture provides a natural explanation of the properties of the Ω(2012)\Omega (2012) state. We stress that the molecular nature of the resonance is revealed with a large coupling of the Ω(2012)\Omega (2012) to the KˉΞ∗\bar{K} \Xi^* channel, that can be observed in the Ω(2012)→KˉπΞ\Omega (2012) \rightarrow \bar{K} \pi \Xi decay which is incorporated automatically in our chiral unitary approach via the use of the spectral function of Ξ∗\Xi^* in the evaluation of the KˉΞ∗\bar{K} \Xi^* loop function.Comment: 11 pages, 8 figure

    Ξc\Xi_c and Ξb\Xi_b excited states within a SU(6)lsf×{\rm SU(6)}_{\rm lsf}\timesHQSS model

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    We study odd parity J=1/2J=1/2 and J=3/2J=3/2 Ξc\Xi_c resonances using a unitarized coupled-channel framework based on a SU(6)lsf×{\rm SU(6)}_{\rm lsf}\timesHQSS-extended Weinberg-Tomozawa baryon-meson interaction, while paying a special attention to the renormalization procedure. We predict a large molecular ΛcKˉ\Lambda_c \bar K component for the Ξc(2790)\Xi_c(2790) with a dominant 0−0^- light-degree-of-freedom spin configuration. We discuss the differences between the 3/2−3/2^- Λc(2625)\Lambda_c(2625) and Ξc(2815)\Xi_c(2815) states, and conclude that they cannot be SU(3) siblings, whereas we predict the existence of other Ξc−\Xi_c-states, two of them related to the two-pole structure of the Λc(2595)\Lambda_c(2595). It is of particular interest a pair of J=1/2J=1/2 and J=3/2J=3/2 poles, which form a HQSS doublet and that we tentatively assign to the Ξc(2930)\Xi_c(2930) and Ξc(2970)\Xi_c(2970), respectively. Within this picture, the Ξc(2930)\Xi_c(2930) would be part of a SU(3) sextet, containing either the Ωc(3090)\Omega_c(3090) or the Ωc(3119)\Omega_c(3119), and that would be completed by the Σc(2800)\Sigma_c(2800). Moreover, we identify a J=1/2J=1/2 sextet with the Ξb(6227)\Xi_b(6227) state and the recently discovered Σb(6097)\Sigma_b(6097). Assuming the equal spacing rule and to complete this multiplet, we predict the existence of a J=1/2J=1/2 Ωb\Omega_b odd parity state, with a mass of 6360 MeV and that should be seen in the ΞbKˉ\Xi_b \bar K channel.Comment: 13 pages, 5 figures, 4 table

    Description of the Ξc\Xi_c and Ξb\Xi_b states as molecular states

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    In this work we study several Ξc\Xi_c and Ξb\Xi_b states dynamically generated from the meson-baryon interaction in coupled channels, using an extension of the local hidden gauge approach in the Bethe-Salpeter equation. These molecular states appear as poles of the scattering amplitudes, and several of them can be identified with the experimentally observed Ξc\Xi_c states, including the Ξc(2790)\Xi_c(2790), Ξc(2930)\Xi_c(2930), Ξc(2970)\Xi_c(2970), Ξc(3055)\Xi_c(3055) and Ξc(3080)\Xi_c(3080). Also, for the recently reported Ξb(6227)\Xi_b(6227) state, we find two poles with masses and widths remarkably close to the experimental data, for both the JP=1/2−J^P=1/2^- and JP=3/2−J^P=3/2^- sectors.Comment: 27 pages, 24 tables, 2 figure
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