Insights into 
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 from dipion transit

Baru, V.; Epelbaum, E.; Filin, A. A.; Hanhart, C.; Mizuk, R.; Nefediev, A. V.; Ropertz, Stefan

doi:10.1103/physrevd.103.034016

“…[83] leading to a J/ψp scattering length of the order of 10 −3 fm). A similar assumption about neglecting the direct interactions between the inelastic Υπ and h b π channels was shown to be consistent with data for the Z b (10610) and Z b (10650) in a combined analysis of the Υ(10860) decays [79], and with the Dalitz plot analysis of the Υππ final states from the Υ(10860) [84]. In addition, we assume that the effect from the interaction of the Λ cD…”

Section: Jhep08(2021)157supporting

confidence: 56%

Revisiting the nature of the Pc pentaquarks

Du

¹

,

Baru

²

,

Guo

³

et al. 2021

J. High Energ. Phys.

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The nature of the three narrow hidden-charm pentaquark Pc states, i.e., Pc(4312), Pc(4440) and Pc(4457), is under intense discussion since their discovery from the updated analysis of the process $$ {\Lambda}_b^0\to J/\psi {pK}^{-} $$ Λ b 0 → J / ψ pK − by LHCb. In this work we extend our previous coupled-channel approach [Phys. Rev. Lett. 124, 072001 (2020)], in which the Pc states are treated as $$ {\Sigma}_c^{\left(\ast \right)}{\overline{D}}^{\left(\ast \right)} $$ Σ c ∗ D ¯ ∗ molecules, by including the $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ Λ c D ¯ ∗ and ηcp 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., $$ {\Sigma}_c^{\left(\ast \right)}{\overline{D}}^{\left(\ast \right)} $$ Σ c ∗ D ¯ ∗ , and inelastic channels and without the $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ Λ c D ¯ ∗ interactions, (b) scheme II, where the one-pion exchange (OPE) is added to scheme I, and (c) scheme III, where the $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ Λ c D ¯ ∗ 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 Pc(4312) and Pc(4440)/Pc(4457) as $$ {\Lambda}_c\overline{D} $$ Λ c D ¯ and $$ {\Sigma}_c{\overline{D}}^{\ast } $$ Σ c D ¯ ∗ hadronic molecules, respectively, and that the data show clear evidence for a new narrow state, Pc(4380), identified as a $$ {\Sigma}_c^{\ast}\overline{D} $$ Σ c ∗ 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 Pc(4440) and Pc(4457) being JP = 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 Pc(4440) and the Pc(4457) in the $$ {\Sigma}_c^{\left(\ast \right)}\overline{D} $$ Σ c ∗ D ¯ and ηcp mass distributions from $$ {\Lambda}_b^0\to {\Sigma}_c^{\left(\ast \right)}\overline{D}{K}^{-} $$ Λ b 0 → Σ c ∗ D ¯ K − and $$ {\Lambda}_b^0\to {\eta}_c{pK}^{-} $$ Λ b 0 → η 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 $$ {\Lambda}_c{\overline{D}}^{\left(\ast \right)} $$ Λ c D ¯ ∗ final states.

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“…It is a natural assumption in the molecular approach that a point-like production mechanism generates first a pair of particles in the elastic channels, which then interact strongly in the final state to produce visible structures in the line shapes near the elastic thresholds. For example, such a production mechanism in the molecular picture provides a very good description of the line shapes for the Z b (10610)/Z b (10650) states measured by Belle [52][53][54] and the pentaquark states discovered by LHCb [55,56]. However, since it is argued in Ref.…”

Section: Production Amplitudementioning

confidence: 99%

“…In particular, we see that once the poles in the 1 +− sector are settled to provide a decent description of the line shapes, those in the 1 ++ and 2 ++ channels are fixed and driven by identical potentials [49,50]. The latter potentials were previously used to a success in studies of the isoscalar states of charmonium (see, e.g., a review article [51] and references therein) and isovector states of bottomonium [52][53][54]. According to Eq.…”

Section: Introductionmentioning

confidence: 99%

Is $Z_{cs}(3982)$ a molecular partner of $Z_c(3900)$ and $Z_c(4020)$ states?

Baru,

Epelbaum,

Filin

et al. 2021

Preprint

Self Cite

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We perform an effective-field-theory-based coupled-channel analysis of the recent BES III data on the e + e − annihilation into the final state) in a wide energy range and extract the poles responsible for the formation of the Z cs (3982). We identify two scenarios which provide a similar description of the experimental mass distributions but result in utterly different predictions for the spin partners of the Z cs (3982): although both scenarios are consistent with the Z cs as a SU (3) partner of the Z c (3900), the Z c (4020) appears naturally as a spin partner of these states only in one of them (fit 1) while in the other (fit 2) its nature has to be different. Also, the Z cs (3982) has a J P = 1 + spin partner near the D * s D * threshold in fit 1, while no such state exists in fit 2. We predict the D * s D * invariant mass distribution in the J P = 1 + channel for the reaction e + e − → K + D * − s D * 0 and argue that this line shape can be used to distinguish between the two scenarios once data in this channel are available.

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“…. Some studies on the πΥ(nS) (n = 1, 2, 3), πh b (mP ) (m = 1, 2), and B ( * ) B( * ) line shapes in the Υ decay can be found in Refs [60,[63][64][65][66][67]…”

mentioning

confidence: 99%

Investigation of the $X(4020)$ peak in the $D^\bar D^$ and $πh_c$ channels

Sakai

¹

2021

Preprint

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In this paper, the nature of X( 4020) observed in the vicinity of the D * D * threshold of the πh c and D * D * distributions is studied. Using a model containing one bare-particle state with the πh c and D * D * one-loop self energies, we make a fit to the πh c and D * D * distributions of the e + e − → π + π − h c and e + e − → π − D * + D * 0 reactions reported by the BESIII Collaboration. It is found that both structures seen in the πh c and D * D * channels are described well with one resonantstate which can be associated with X(4020) while the obtained X(4020) mass and width are found to be larger than those in the latest PDG. We evaluate the scattering length and effective range of the S-wave D * D * pair with spin J = 1 related to the X(4020) properties which can be tested with model calculations or future lattice QCD study. Our analysis suggests that a large part of X(4020) may come from a bare-particle state originating from some short-range dynamics other than the D * D * channel.

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Insights into Zb(10610) and Zb(10650) from dipion transit

Cited by 11 publications

References 52 publications

Revisiting the nature of the Pc pentaquarks

Revisiting the nature of the Pc pentaquarks

Is $Z_{cs}(3982)$ a molecular partner of $Z_c(3900)$ and $Z_c(4020)$ states?

Investigation of the $X(4020)$ peak in the $D^\bar D^$ and $πh_c$ channels

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Insights into Zb(10610) and Zb(10650) from dipion transit

Cited by 11 publications

References 52 publications

Revisiting the nature of the Pc pentaquarks

Revisiting the nature of the Pc pentaquarks

Is $Z_{cs}(3982)$ a molecular partner of $Z_c(3900)$ and $Z_c(4020)$ states?

Investigation of the $X(4020)$ peak in the $D^*\bar D^*$ and $πh_c$ channels

Contact Info

Product

Resources

About

Investigation of the $X(4020)$ peak in the $D^\bar D^$ and $πh_c$ channels