Rui Chen^{1}

Abstract: Stimulated by the ${P}_{cs}(4459)$ reported by the LHCb collaboration, we perform a single ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ channel and a coupled ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}/{\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}/{\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}/{\mathrm{\ensuremath{\Xi}}}_{c}^{*}{\overline{D}}^{*}$ channel analysis by using a one-boson-exchange model. Our results indicate that the newly ${P}_{cs}(4459)$ cannot be a pure ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ molecular state, but a coupled ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}/{\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}/{\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}/{\mathrm{\ensuremath{\Xi}}}_{c}^{*}{\overline{D}}^{*}$ bound state with $I({J}^{P})=0(3/{2}^{\ensuremath{-}})$, where the ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ and ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}$ components are dominant. Meanwhile, we find the interactions from the ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}$ system with $0(1/{2}^{\ensuremath{-}})$, the ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}$ system with $1(3/{2}^{\ensuremath{-}})$, and the ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}{\overline{D}}^{*}$ system with $1(1/{2}^{\ensuremath{-}})$ are strongly attractive, where one can expect possible strange hidden-charm molecular or resonant structures near these thresholds with the assigned quantum numbers.

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17 results found

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01 Jan 2012-

Abstract: Using the one-boson-exchange model,we studied the possible existence of very loosely bound hidden-charm molecular baryons composed of an anti-charmed meson and a charmed baryon.Our numerical results indicate that the Σ c * and Σ c states exist,but that the Λ c and Λ c * molecular states do not.

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Topics: Charm (quantum number) (64%), Meson (58%), Baryon (57%)

52 Citations

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Abstract: Recently, the LHCb Collaboration reported a new structure Pcs(4459) with a mass of 19 MeV below the ΞcD¯* threshold It may be a candidate of molecular state from the ΞcD¯* interaction In the current work, we perform a coupled-channel study of the Ξc*D¯*, Ξc′D¯*, Ξc*D¯, ΞcD¯*, Ξc′D¯, and ΞcD¯ interactions in the quasipotential Bethe-Salpeter equation approach With the help of the heavy quark chiral effective Lagrangian, the potential is constructed by light meson exchanges Two ΞcD¯* molecular states are produced with spin parities JP=1/2- and 3/2- The lower state with 3/2- can be related to the observed Pcs(4450) while two-peak structure cannot be excluded Within the same model, other strange hidden-charm pentaquarks are also predicted Two states with spin parities 1/2- and a state with 3/2- are predicted near the Ξc′D¯, ΞcD¯, and Ξc*D¯ thresholds, respectively As two states near ΞcD¯* threshold, two states are produced with 1/2- and 3/2- near the Ξc′D¯* threshold The couplings of the molecular states to the considered channels are also discussed The experimental research of those states are helpful to understand the origin and internal structure of the Pcs and Pc states

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12 Citations

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Abstract: In this work, we investigate the SU(3) flavor symmetry, heavy quark spin symmetry and their breaking effects in the di-meson systems. We prove the existence of the $[\bar{D}_{s}^{*}D_{s}^{*}]^{0^{++}}$, $[\bar{D}_{s}^{*}D_{s}/\bar{D}_{s}^{}D_{s}^*]^{1^{+-}}$, and $[\bar{D}_{s}^{*}D_{s}^{*}]^{1^{+-}}$ bound states as the consequence of two prerequisites in the SU(3) flavor symmetry and heavy quark spin symmetry. The first prerequisite, the $X(3872)$ as the weakly $\bar{D}^{*}D/\bar{D} D^{*}$ bound state is supported by its mass and decay branching ratios. The second prerequisite, the existence of the $[\bar{D}_{s}D_{s}]^{0^{++}}$ bound state is supported by the lattice QCD calculation [arXiv:2011.02542(hep-lat)] and the observation of $\chi_{c0}(3930)$ by the LHCb Collaboration[Phys.Rev.Lett.125,242001, Phys.Rev.D102,112003]. We hope the future experimental analyses can search for these bound states in the $B\to D_{(s)}^{(*)}\bar{D}^{(*)}_{(s)}h$ processes ($h$ denotes the light hadrons). The $[\bar{D}_{s}^{*}D_{s}^{*}]^{0^{++}}$ bound state is also expected to be reconstructed in the $J/\psi \phi$ final state in the $B\to J/\psi \phi K$ decay.

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9 Citations

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Abstract: Recently, the LHCb Collaboration reported a new structure ${P}_{cs}(4459)$ with a mass of 19 MeV below the ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ threshold. It may be a candidate of molecular state from the ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ interaction. In the current work, we perform a coupled-channel study of the ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}{\overline{D}}^{*}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}$, ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$, ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}\overline{D}$, and ${\mathrm{\ensuremath{\Xi}}}_{c}\overline{D}$ interactions in the quasipotential Bethe-Salpeter equation approach. With the help of the heavy quark chiral effective Lagrangian, the potential is constructed by light meson exchanges. Two ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ molecular states are produced with spin parities ${J}^{P}=1/{2}^{\ensuremath{-}}$ and $3/{2}^{\ensuremath{-}}$. The lower state with $3/{2}^{\ensuremath{-}}$ can be related to the observed ${P}_{cs}(4450)$ while two-peak structure cannot be excluded. Within the same model, other strange hidden-charm pentaquarks are also predicted. Two states with spin parities $1/{2}^{\ensuremath{-}}$ and a state with $3/{2}^{\ensuremath{-}}$ are predicted near the ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}\overline{D}$, ${\mathrm{\ensuremath{\Xi}}}_{c}\overline{D}$, and ${\mathrm{\ensuremath{\Xi}}}_{c}^{*}\overline{D}$ thresholds, respectively. As two states near ${\mathrm{\ensuremath{\Xi}}}_{c}{\overline{D}}^{*}$ threshold, two states are produced with $1/{2}^{\ensuremath{-}}$ and $3/{2}^{\ensuremath{-}}$ near the ${\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}}{\overline{D}}^{*}$ threshold. The couplings of the molecular states to the considered channels are also discussed. The experimental research of those states are helpful to understand the origin and internal structure of the ${P}_{cs}$ and ${P}_{c}$ states.

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9 Citations

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Abstract: In this work, we investigate the SU(3) flavor symmetry, heavy quark spin symmetry and their breaking effects in the di-meson systems. We prove the existence of the [ D ‾ s ∗ D s ∗ ] 0 + + , [ D ‾ s ∗ D s / D ‾ s D s ∗ ] 1 + - , and [ D ‾ s ∗ D s ∗ ] 1 + - bound states as the consequence of two prerequisites in the SU(3) flavor symmetry and heavy quark spin symmetry. The first prerequisite, the X ( 3872 ) as the weakly D ‾ ∗ D / D ‾ D ∗ bound state is supported by its mass and decay branching ratios. The second prerequisite, the existence of the [ D ‾ s D s ] 0 + + bound state is supported by the lattice QCD calculation and the observation of χ c 0 ( 3930 ) by the LHCb Collaboration. We hope the future experimental analyses can search for these bound states in the B → D ( s ) ( * ) D ‾ ( s ) ( * ) h processes (h denotes the light hadrons). The [ D ‾ s ∗ D s ∗ ] 0 + + bound state is also expected to be reconstructed in the J / ψ ϕ final state in the B → J / ψ ϕ K decay.

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8 Citations

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66 results found

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01 Aug 2020-

1,155 Citations

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Abstract: In the past decade many charmonium-like states were observed experimentally. Especially those charged charmonium-like Zc states and bottomonium-like Zb states cannot be accommodated within the naive quark model. These charged Zc states are good candidates of either the hidden-charm tetraquark states or molecules composed of a pair of charmed mesons. Recently, the LHCb Collaboration discovered two hidden-charm pentaquark states, which are also beyond the quark model. In this work, we review the current experimental progress and investigate various theoretical interpretations of these candidates of the multiquark states. We list the puzzles and theoretical challenges of these models when confronted with the experimental data. We also discuss possible future measurements which may distinguish the theoretical schemes on the underlying structures of the hidden-charm multiquark states.

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Topics: Tetraquark (58%), Z(4430) (57%), Pentaquark (53%) ... show more

771 Citations

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Roel Aaij^{1}, Bernardo Adeva^{2}, Marco Adinolfi^{3}, A. A. Affolder^{4} +719 more•Institutions (49)

Abstract: Observations of exotic structures in the J/ψp channel, that we refer to as pentaquark-charmonium states, in Λ0b→J/ψK−p decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final-state that reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/ψp mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380±8±29 MeV and a width of 205±18±86 MeV, while the second is narrower, with a mass of 4449.8±1.7±2.5 MeV and a width of 39±5±19 MeV. The preferred JP assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.

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Topics: Pentaquark (53%), Meson (53%), Hadron (52%) ... show more

732 Citations

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Abstract: A large number of experimental discoveries especially in the heavy quarkonium sector that did not at all fit to the expectations of the until then very successful quark model led to a renaissance of hadron spectroscopy Among various explanations of the internal structure of these excitations, hadronic molecules, being analogues of light nuclei, play a unique role since for those predictions can be made with controlled uncertainty We review experimental evidences of various candidates of hadronic molecules, and methods of identifying such structures Nonrelativistic effective field theories are the suitable framework for studying hadronic molecules, and are discussed in both the continuum and finite volumes Also pertinent lattice QCD results are presented Further, we discuss the production mechanisms and decays of hadronic molecules, and comment on the reliability of certain assertions often made in the literature

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Topics: Lattice QCD (52%)

680 Citations

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Abstract: An effective Lagrangian that describes the low-momentum interactions of mesons containing a heavy quark with the pseudo Goldstone bosons $\ensuremath{\pi}$, $K$, and $\ensuremath{\eta}$ is constructed. It is invariant under both heavy-quark spin symmetry and chiral ${\mathrm{SU}(3)}_{L}\ifmmode\times\else\texttimes\fi{}{\mathrm{SU}(3)}_{R}$ symmetry. Implications for semileptonic $B$ and $D$ decays are discussed.

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Topics: Chiral perturbation theory (52%), Quantum chromodynamics (50%), Quark model (50%) ... show more

449 Citations