In a recent paper [<a href="http://dx.doi.org/10.1103/PhysRevLett.126.132001">Phys. Rev. Lett. 126, 132001 (2021)</a>], the LHCb data on the di-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> production in proton-proton collisions were analyzed in a coupled-channel framework based on double-vector-charmonium channels. This investigation identified a robust pole near the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>J</mi><mo>/</mo><mi>ψ</mi></math> threshold, tagged <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>X</mi><mo stretchy="false">(</mo><mn>6200</mn><mo stretchy="false">)</mo></math>, suggesting it as a new state. The present work extends that investigation by incorporating recent di-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> production data from the CMS and ATLAS Collaborations and performing a combined analysis of all three datasets. This study confirms the existence of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>X</mi><mo stretchy="false">(</mo><mn>6200</mn><mo stretchy="false">)</mo></math>, and its pole position is now determined with a higher precision than in the previous study, where only a single dataset was employed. The pole corresponding to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>X</mi><mo stretchy="false">(</mo><mn>6900</mn><mo stretchy="false">)</mo></math> is also extracted, though its actual position and residue depend on a particular coupled-channel model employed and deviate from values reported in the experimental investigations. Moreover, we demonstrate that the currently available data do not allow one to determine whether there is an additional pole in the studied mass range. The dielectron width of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>X</mi><mo stretchy="false">(</mo><mn>6200</mn><mo stretchy="false">)</mo></math> is estimated under different conjectures on its quantum numbers, and the number of such states that can be annually produced at the future Super <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math>-Charm Facility is estimated. The line shape in the complimentary <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo></math> channel is discussed, and a good agreement with the ATLAS data is found.

China

Yi-Lin Song

Yu Zhang

Germany

Vadim Baru

Feng-Kun Guo

Christoph Hanhart

Portugal

Alexey Nefediev

Toward a precision determination of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>X</mi><mo stretchy="false">(</mo><mn>6200</mn><mo stretchy="false">)</mo></mrow></math> parameters from data

Experimentally, the doubly charm tetraquark channel <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mi>c</mi><mover accent="true"><mi>q</mi><mo stretchy="false">¯</mo></mover><mover accent="true"><mi>q</mi><mo stretchy="false">¯</mo></mover></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>q</mi><mo>=</mo><mi>u</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>d</mi></mrow></math> features an exotic hadron, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub></math>, with isospin <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math> near the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msup><mi>D</mi><mo>*</mo></msup></math> threshold, while no peak was observed for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn></math>. We present a lattice QCD study of this channel with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mn>1</mn><mo>+</mo></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>π</mi></msub><mo>≃</mo><mn>280</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>. Finite-volume energies calculated across five charm quark masses consistently feature a positive energy shift with respect to noninteracting energies, indicating repulsive interaction at energies near the threshold. These energies are used to compute the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msup><mi>D</mi><mo>*</mo></msup></math> scattering amplitude using both the standard Lüscher method and the recently proposed effective field theory-based approach in the plane wave basis, which incorporates the long-range interactions and the left-hand cut. Both analyses render a small negative scattering length and a scattering amplitude that does not feature any poles in the energy region near the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msup><mi>D</mi><mo>*</mo></msup></math> threshold, in line with the LHCb results. We identify that the Wick contraction, resembling <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-channel isovector-vector meson exchanges between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup></math>, plays a key role in distinguishing between the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn></math> channels, leading to repulsion in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn></math> and attraction in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math> channel.

Lu Meng

Slovenia

United States

Emmanuel Ortiz-Pacheco

Evgeny Epelbaum

India

M. Padmanath

Sasa Prelovsek

Doubly charm tetraquark channel with isospin 1 from lattice QCD

We employ a chiral effective field theory-based approach to connect <math><mi>D</mi><msup><mrow><mi>D</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math> scattering observables at the physical and variable pion masses accessible in lattice QCD simulations. We incorporate all relevant scales associated with three-body DDπ dynamics and the left-hand cut induced by the one-pion exchange for pion masses higher than the physical one, as required by analyticity and unitarity. By adjusting the contact interactions to match experimental data at the physical pion mass and lattice finite-volume energy levels at <math><msub><mrow><mi>m</mi></mrow><mrow><mi>π</mi></mrow></msub><mo>=</mo><mn>280</mn></math> MeV, we predict the trajectory of the <math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi><mi>c</mi></mrow></msub></math> pole as a function of the pion mass, finding it consistent with the hadronic-molecule scenario. In particular, we find that the explicit treatment of the one-pion exchange has a pronounced effect on the pole trajectory for <math><msub><mrow><mi>m</mi></mrow><mrow><mi>π</mi></mrow></msub><mo>≳</mo><mn>230</mn></math> MeV by pushing it into the complex energy plane.

Michael Abolnikov

Arseniy A. Filin

Internal structure of the (3875) From its Light-quark Mass Dependence

We demonstrate that the dip observed near the total energy of 3872 MeV in the recent cross section data from the BESIII Collaboration for <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo>→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> admits a natural explanation as a coupled-channel effect: it is a consequence of unitarity and a strong <math><mi>S</mi></math>-wave <math><mi>D</mi><msup><mover><mi>D</mi><mo>¯</mo></mover><mo>*</mo></msup></math> attraction that generates the state <math><mi>X</mi><mo>(</mo><mn>3872</mn><mo>)</mo></math>. We anticipate the appearance of a similar dip in the <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo>→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><msup><mi>π</mi><mn>0</mn></msup></math> final state near the <math><msup><mi>D</mi><mo>*</mo></msup><msup><mover><mi>D</mi><mo>¯</mo></mover><mo>*</mo></msup></math> threshold driven by the same general mechanism, then to be interpreted as a signature of the predicted spin-2 partner of the <math><mi>X</mi><mo>(</mo><mn>3872</mn><mo>)</mo></math>.

How does the <math><mi>X</mi><mo>(</mo><mn>3872</mn><mo>)</mo></math> show up in <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> collisions: Dip versus peak

In recent years many vector charmonium(like) states were reported by different electron-positron collider experiments above 4.2 GeV. However, so far, there not only exists sizable tension in the parameters of those states, but there is also no consensus on the number of the vector states in this energy range. To some extend, this might be caused by the fact that the experimental data were typically analyzed in single channel analyses employing overlapping Breit-Wigner functions, in particular ignoring the effect of opening thresholds. In this study, we focus on the mass range between 4.2 GeV and 4.35 GeV, conducting a comprehensive analysis of eight different final states in <math><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> annihilation. Our findings demonstrate that, within this mass range, a single vector charmoniumlike state, exhibiting properties consistent with a <math><mrow><msub><mrow><mi>D</mi></mrow><mrow><mn>1</mn></mrow></msub><mover><mrow><mi>D</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow></math> molecular structure and characterized by a pole location <math><mrow><msqrt><mrow><msubsup><mrow><mi>s</mi></mrow><mrow><mi>pole</mi></mrow><mrow><mi>Y</mi><mo>(</mo><mn>4230</mn><mo>)</mo></mrow></msubsup></mrow></msqrt><mo>=</mo><mrow><mo>(</mo><mn>4227</mn><mo>±</mo><mn>4</mn><mo>−</mo><mfrac><mrow><mi>i</mi></mrow><mrow><mn>2</mn></mrow></mfrac><mo>(</mo><msubsup><mrow><mn>50</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow><mrow><mo>+</mo><mn>8</mn></mrow></msubsup><mo>)</mo><mo>)</mo><mtext> </mtext><mtext> </mtext><mi>MeV</mi></mrow></mrow></math>, can effectively describe all the collected data. This is made possible by allowing for an interference with the well-established vector charmonium <math><mi>ψ</mi><mo>(</mo><mn>4160</mn><mo>)</mo></math> along with the inclusion of the <math><msub><mi>D</mi><mn>1</mn></msub><mover><mi>D</mi><mo>¯</mo></mover></math> threshold effect. Moreover, in contrast to experimental analyses, our study reveals that the highly asymmetric total cross sections for <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo>→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>π</mi><mi>π</mi></math> and <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo>→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>K</mi><mover><mi>K</mi><mo>¯</mo></mover></math> around 4230 MeV stem from the same physics, rooted in the approximate SU(3) flavor symmetry of QCD.

Leon von Detten

Qian Wang

Daniel Winney

Qiang Zhao

How many vector charmoniumlike states lie in the mass range 4.2–4.35 GeV?

We discuss a novel effective-field-theory-based approach for extracting two-body scattering information from finite volume energies, serving as an alternative to Lüscher’s method. By explicitly incorporating one-pion exchange, we overcome the challenging left-hand cut problem in Lüscher’s method and can handle finite volume energy levels both below and above the left-hand cut. Applied to the lattice data for <math><mi>D</mi><msup><mi>D</mi><mo>*</mo></msup></math> scattering at a pion mass of 280 MeV, as an illustrative example, our results reveal the significant impact of the one-pion exchange on <math><mi>P</mi></math>-wave and <math><mi>S</mi></math>-wave phase shifts. The pole position of the <math><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo>(</mo><mn>3875</mn><msup><mo>)</mo><mo>+</mo></msup></math> state, extracted from the finite-volume energy levels at this pion mass while taking into account left-hand cut effects, range corrections and partial-wave mixing, is consistent with a near-threshold resonance. This study demonstrates, for the first time, that two-body scattering information can be reliably extracted from lattice spectra including the left-hand cut.

Ashot M. Gasparyan

Solving the left-hand cut problem in lattice QCD: <math><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo>(</mo><mn>3875</mn><msup><mo>)</mo><mo>+</mo></msup></math> from finite volume energy levels

We discuss recent lattice data for the <math><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo>(</mo><mn>3875</mn><msup><mo>)</mo><mo>+</mo></msup></math> state to stress, for the first time, a potentially strong impact of left-hand cuts from the one-pion exchange on the pole extraction for near-threshold exotic states. In particular, if the left-hand cut is located close to the two-particle threshold, which happens naturally in the <math><mi>D</mi><msup><mi>D</mi><mo>*</mo></msup></math> system for the pion mass exceeding its physical value, the effective-range expansion is valid only in a very limited energy range up to the cut and as such is of little use to reliably extract the poles. Then, an accurate extraction of the pole locations requires the one-pion exchange to be implemented explicitly into the scattering amplitudes. Our findings are general and potentially relevant for a wide class of hadronic near-threshold states.

Meng-Lin Du

Arseniy Filin

Xiang-Kun Dong

Spain

Juan Nieves

Role of Left-Hand Cut Contributions on Pole Extractions from Lattice Data: Case Study for <math><msub><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo>(</mo><mn>3875</mn><msup><mo>)</mo><mo>+</mo></msup></math>

We discuss some general features of the effective range expansion, the content of its parameters with respect to the nature of the pertinent near-threshold states and the necessary modifications in the presence of coupled channels, isospin violations and unstable constituents. As illustrative examples, we analyse the properties of the <math><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo>(</mo><mn>3872</mn><mo>)</mo></math> and <math><msubsup><mrow><mi>T</mi></mrow><mrow><mi>c</mi><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup></math> states supporting the claim that these exotic states have a predominantly molecular nature.

Effective range expansion for narrow near-threshold resonances

A coupled-channel approach is applied to the charged tetraquark state <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> recently discovered by the LHCb Collaboration. The parameters of the interaction are fixed by a fit to the observed line shape in the three-body <math><msup><mi>D</mi><mn>0</mn></msup><msup><mi>D</mi><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> channel. Special attention is paid to the three-body dynamics in the <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> due to the finite life time of the <math><msup><mi>D</mi><mo>*</mo></msup></math>. An approach to the <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> is argued to be self-consistent only if both manifestations of the three-body dynamics, the pion exchange between the <math><mi>D</mi></math> and <math><msup><mi>D</mi><mo>*</mo></msup></math> mesons and the finite <math><msup><mi>D</mi><mo>*</mo></msup></math> width, are taken into account simultaneously to ensure that three-body unitarity is preserved. This is especially important to precisely extract the pole position in the complex energy plane whose imaginary part is very sensitive to the details of the coupled-channel scheme employed. The <math><msup><mi>D</mi><mn>0</mn></msup><msup><mi>D</mi><mn>0</mn></msup></math> and <math><msup><mi>D</mi><mn>0</mn></msup><msup><mi>D</mi><mo>+</mo></msup></math> invariant mass distributions, predicted based on this analysis, are in good agreement with the LHCb data. The low-energy expansion of the <math><msup><mi>D</mi><mo>*</mo></msup><mi>D</mi></math> scattering amplitude is performed and the low-energy constants (the scattering length and effective range) are extracted. The compositeness parameter of the <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> is found to be close to unity, which implies that the <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> is a hadronic molecule generated by the interactions in the <math><msup><mi>D</mi><mrow><mo>*</mo><mo>+</mo></mrow></msup><msup><mi>D</mi><mn>0</mn></msup></math> and <math><msup><mi>D</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><msup><mi>D</mi><mo>+</mo></msup></math> channels. Employing heavy-quark spin symmetry, an isoscalar <math><msup><mi>D</mi><mo>*</mo></msup><msup><mi>D</mi><mo>*</mo></msup></math> molecular partner of the <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> with <math><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mn>1</mn><mo>+</mo></msup></math> is predicted under the assumption that the <math><mrow><mi>D</mi><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo></mrow></msup><mtext>−</mtext><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo></mrow></msup><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo></mrow></msup></mrow></math> coupled-channel effects can be neglected.

Russia

Coupled-channel approach to <math><msubsup><mi>T</mi><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> including three-body effects

The nature of the three narrow hidden-charm pentaquark P c states, i.e., P c (4312), P c (4440) and P c (4457), is under intense discussion since their discovery from the updated analysis of the process <math> <msubsup> <mi>Λ</mi> <mi>b</mi> <mn>0</mn> </msubsup> <mo>→</mo> <mi>J</mi> <mo>/</mo> <mi>ψ</mi> <msup> <mi>pK</mi> <mo>−</mo> </msup> </math> $$ {\Lambda}_b^0\to J/\psi {pK}^{-} $$ by LHCb. In this work we extend our previous coupled-channel approach [Phys. Rev. Lett. 124, 072001 (2020)], in which the P c states are treated as <math> <msubsup> <mi>Σ</mi> <mi>c</mi> <mfenced> <mo>∗</mo> </mfenced> </msubsup> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mfenced> <mo>∗</mo> </mfenced> </msup> </math> $$ {\Sigma}_c^{\left(\ast \right)}{\overline{D}}^{\left(\ast \right)} $$ molecules, by including the <math> <msub> <mi>Λ</mi> <mi>c</mi> </msub> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mfenced> <mo>∗</mo> </mfenced> </msup> </math> $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ and η c p as explicit inelastic channels in addition to the J/ψp, as required by unitarity and heavy quark spin symmetry (HQSS), respectively. Since inelastic parameters are very badly constrained by the current data, three calculation schemes are considered: (a) scheme I with pure contact interactions between the elastic, i.e., <math> <msubsup> <mi>Σ</mi> <mi>c</mi> <mfenced> <mo>∗</mo> </mfenced> </msubsup> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mfenced> <mo>∗</mo> </mfenced> </msup> </math> $$ {\Sigma}_c^{\left(\ast \right)}{\overline{D}}^{\left(\ast \right)} $$ , and inelastic channels and without the <math> <msub> <mi>Λ</mi> <mi>c</mi> </msub> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mfenced> <mo>∗</mo> </mfenced> </msup> </math> $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ interactions, (b) scheme II, where the one-pion exchange (OPE) is added to scheme I, and (c) scheme III, where the <math> <msub> <mi>Λ</mi> <mi>c</mi> </msub> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mfenced> <mo>∗</mo> </mfenced> </msup> </math> $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ interactions are included in addition. It is shown that to obtain cutoff independent results, OPE in the multichannel system is to be supplemented with S-wave-to-D-wave mixing contact terms. As a result, in line with our previous analysis, we demonstrate that the experimental data for the J/ψp invariant mass distribution are consistent with the interpretation of the P c (4312) and P c (4440)/P c (4457) as <math> <msub> <mi>Λ</mi> <mi>c</mi> </msub> <mover> <mi>D</mi> <mo>¯</mo> </mover> </math> $$ {\Lambda}_c\overline{D} $$ and <math> <msub> <mi>Σ</mi> <mi>c</mi> </msub> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mo>∗</mo> </msup> </math> $$ {\Sigma}_c{\overline{D}}^{\ast } $$ hadronic molecules, respectively, and that the data show clear evidence for a new narrow state, P c (4380), identified as a <math> <msubsup> <mi>Σ</mi> <mi>c</mi> <mo>∗</mo> </msubsup> <mover> <mi>D</mi> <mo>¯</mo> </mover> </math> $$ {\Sigma}_c^{\ast}\overline{D} $$ molecule, which should exist as a consequence of HQSS. While two statistically equally good solutions are found in scheme I, only one of these solutions with the quantum numbers of the P c (4440) and P c (4457) being J P = 3/2 − and 1/2 − , respectively, survives the requirement of regulator independence once the OPE is included. Moreover, we predict the line shapes in the elastic and inelastic channels and demonstrate that those related to the P c (4440) and the P c (4457) in the <math> <msubsup> <mi>Σ</mi> <mi>c</mi> <mfenced> <mo>∗</mo> </mfenced> </msubsup> <mover> <mi>D</mi> <mo>¯</mo> </mover> </math> $$ {\Sigma}_c^{\left(\ast \right)}\overline{D} $$ and η c p mass distributions from <math> <msubsup> <mi>Λ</mi> <mi>b</mi> <mn>0</mn> </msubsup> <mo>→</mo> <msubsup> <mi>Σ</mi> <mi>c</mi> <mfenced> <mo>∗</mo> </mfenced> </msubsup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <msup> <mi>K</mi> <mo>−</mo> </msup> </math> $$ {\Lambda}_b^0\to {\Sigma}_c^{\left(\ast \right)}\overline{D}{K}^{-} $$ and <math> <msubsup> <mi>Λ</mi> <mi>b</mi> <mn>0</mn> </msubsup> <mo>→</mo> <msub> <mi>η</mi> <mi>c</mi> </msub> <msup> <mi>pK</mi> <mo>−</mo> </msup> </math> $$ {\Lambda}_b^0\to {\eta}_c{pK}^{-} $$ will shed light on the quantum numbers of those states, once the data are available. We also investigate possible pentaquark signals in the <math> <msub> <mi>Λ</mi> <mi>c</mi> </msub> <msup> <mover> <mi>D</mi> <mo>¯</mo> </mover> <mfenced> <mo>∗</mo> </mfenced> </msup> </math> $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ final states.

Georgia

Ulf-G. Meißner

José Oller

Revisiting the nature of the P  c  pentaquarks