Towards a theory of hadron resonances

Mai, Maxim; Meißner, Ulf‐G.; Urbach, Carsten

doi:10.1016/j.physrep.2022.11.005

Cited by 49 publications

(12 citation statements)

References 458 publications

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“…For a review of the current status of computations of three-particle scattering amplitudes using the finite-volume approach, see the presentation by F. Romero-López and the recent reviews in Refs. [22,23].…”

Section: Discussionmentioning

confidence: 99%

The spectral reconstruction of inclusive rates

Bulava¹

2023

Proceedings of the 39th International Symposium on Lattice Field Theory — PoS(LATTICE2022)

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A recently re-discovered variant of the Backus-Gilbert algorithm for spectral reconstruction enables the controlled determination of smeared spectral densities from lattice field theory correlation functions. A particular advantage of this approach is the a priori specification of the kernel with which the underlying spectral density is smeared, allowing for variation of its peak position, smearing width, and functional form. If the unsmeared spectral density is sufficiently smooth in the neighborhood of a particular energy, it can be obtained from an extrapolation to zero smearing-kernel width at fixed peak position. A natural application for this approach is scattering processes summed over all hadronic final states. As a proof-of-principle test, an inclusive rate is computed in the two-dimensional O(3) sigma model from a two-point correlation function of conserved currents. The results at finite and zero smearing radius are in good agreement with the known analytic form up to energies at which 40-particle states contribute, and are sensitive to the 4-particle contribution to the inclusive rate. The straight-forward adaptation to compute the 𝑅-ratio in lattice QCD from two-point functions of the electromagnetic current is briefly discussed.

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Section: Discussionmentioning

confidence: 99%

The spectral reconstruction of inclusive rates

Bulava¹

2023

Proceedings of the 39th International Symposium on Lattice Field Theory — PoS(LATTICE2022)

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“…As the thresholds of the inelastic channels J/ψp and η c p are far away from those of elastic channels, their effects on the classification of the poles relevant to the physical observables are marginal. The 1 2 − and 3 2 − states are given by a three-channel case with 2 3 = 8 Riemann surfaces denoted as R ±±± , see [19] for a pictorial. Here, the "+" and "-" signs in the ith position mean the physical and unphysical sheet of the ith channel, respectively.…”

Section: States and Labelsmentioning

confidence: 99%

“…Since then, many interpretations were proposed for these states, e.g. compact multi-quark, hadronic molecule, hybrid, and triangle singularity [9][10][11][12][13][14][15][16][17][18][19]. Traditionally, judging whether a model works or not is to compare it with the experimental data.…”

Section: Introductionmentioning

confidence: 99%

Revealing the nature of hidden charm pentaquarks with machine learning

Zhang¹,

Hu²,

Wang³

et al. 2023

Preprint

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We study the nature of the hidden charm pentaquarks, i.e. the Pc(4312), Pc(4440) and Pc(4457), with a neural network approach in pionless effective field theory. In this framework, the normal χ 2 fitting approach cannot distinguish the quantum numbers of the Pc(4440) and Pc(4457). In contrast to that, the neural network-based approach can discriminate them. In addition, we also illustrate the role of each experimental data bin of the invariant J/ψp mass distribution on the underlying physics in both neural network and fitting methods. Their similarities and differences demonstrate that neural network methods can use data information more effectively and directly. This study provides more insights about how the neural network-based approach predicts the nature of exotic states from the mass spectrum.

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“…The lattice QCD and effective field theory methods to study hadron spectroscopy have been recently reviewed in e.g. [1][2][3].…”

Section: Theoretical Approaches and Examplesmentioning

confidence: 99%