Further study of the I = 1K structure near threshold

Astier, A.; Cohen-Ganouna, J.; Negra, M. Della; Maréchal, B.; Montanet, L.; Tomás, Manuel Pruñonosa; Baubillier, M.; Duboc, J.

doi:10.1016/0370-2693(67)90020-2

Cited by 63 publications

(27 citation statements)

References 3 publications

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“…A priori, one would expect the intermediateūd-like scalar to strongly couple to the K − K 0 system [82]. We emphasize that the value at the origin of the K − K 0 SFF, as computed from RChT in a similar way to Eq.…”

Section: Two Coupled Channelsmentioning

confidence: 91%

Predictions on the second-class current decaysτ−→π−η(′)<

Escribano¹,

2016

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We analyze the second-class current decays τ − → π − η ( ) ν τ in the framework of Chiral Perturbation Theory with resonances. Taking into account π 0 -η-η mixing, the π − η ( ) vector form factor is extracted, in a model-independent way, using existing data on the π − π 0 one. For the participant scalar form factor, we have considered different parameterizations ordered according to their increasing fulfillment of analyticity and unitarity constraints. We start with a Breit-Wigner parameterization dominated by the a 0 (980) scalar resonance and after we include its excited state, the a 0 (1450). We follow by an elastic dispersion relation representation through the Omnès integral. Then, we illustrate a method to derive a closed-form expression for the π − η, π − η (and K − K 0 ) scalar form factors in a coupled-channels treatment. Finally, predictions for the branching ratios and spectra are discussed emphasizing the error analysis. An interesting result of this study is that both τ − → π − η ( ) ν τ decay channels are promising for the soon discovery of second-class currents at Belle-II. We also predict the relevant observables for the partner η ( ) 3 decays, which are extremely suppressed in the Standard Model. * rescriba@ifae.es † sgonzalez@ifae.cat ‡ proig@fis.cinvestav.mx 1 arXiv:1601.03989v2 [hep-ph]

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Section: Two Coupled Channelsmentioning

confidence: 91%

Predictions on the second-class current decaysτ−→π−η(′)<

Escribano¹,

2016

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“…This amplitude features 9 real parameters: a mass and three channel couplings for each real pole plus a constant to allow for some gentle ηη energy dependence. This form allows the ηη channel to decouple if the fit selects small values for the relevant pole couplings (g (1,2) ηη ). The description of the lattice QCD spectra provided by this amplitude, with a χ 2 /N dof = 28.9/(34 − 9) = 1.15, is shown in Figure 11.…”

Section: Coupled D-wave ππ Kk ηη Scatteringmentioning

confidence: 99%

Isoscalar ππ, KK¯, ηη scattering and the
Briceño
¹
,
Dudek
²
,
Edwards
³

et al. 2018
Phys. Rev. D

134

121

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We present the first lattice QCD study of coupled isoscalar ππ; KK; ηη S-and D-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the light quark mass corresponding to m π ∼ 391 MeV. In the J P ¼ 0 þ sector we find analogues of the experimental σ and f 0 ð980Þ states, where the σ appears as a stable bound-state below ππ threshold, and, similar to what is seen in experiment, the f 0 ð980Þ manifests itself as a dip in the ππ cross section in the vicinity of the KK threshold. For J P ¼ 2 þ we find two states resembling the f 2 ð1270Þ and f 0 2 ð1525Þ, observed as narrow peaks, with the lighter state dominantly decaying to ππ and the heavier state to KK. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.

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“…The interpretation of these states, and the existence of the strange analog state, κ, remain open issues [141]. In the intervening decades, the idea of multiquark states has been applied to a host of additional states -a 0 and f 0 (KK) [142,143], f 1 (1420) (K * K) [144], f 2 (2010) (φφ) [145], f 0 (1770) (K * K * ) [146], ψ(4040) (D * D * ) [147], X(3872) (DD * ) [148] with many similar guesses for the current crop of "X, Y, Z" states [149].…”

Section: Multiquarksmentioning

confidence: 99%

Physics opportunities with meson beams

et al. 2015

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Over the past two decades, meson photo-and electroproduction data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even nonexistent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a stateof-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.

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Further study of the I = 1K structure near threshold

Cited by 63 publications

References 3 publications

Predictions on the second-class current decaysτ−→π−η(′)<

Predictions on the second-class current decaysτ−→π−η(′)<

Isoscalar ππ, KK¯, ηη scattering and the
Briceño
¹
,
Dudek
²
,
Edwards
³

et al. 2018
Phys. Rev. D

Physics opportunities with meson beams

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Further study of the I = 1K structure near threshold

Cited by 63 publications

References 3 publications

Predictions on the second-class current decaysτ−→π−η(′)<

Predictions on the second-class current decaysτ−→π−η(′)<

Isoscalar ππ, KK¯, ηη scattering and the Briceño1, Dudek2, Edwards3 et al. 2018Phys. Rev. D

Physics opportunities with meson beams

Contact Info

Product

Resources

About

Isoscalar ππ, KK¯, ηη scattering and the
Briceño
¹
,
Dudek
²
,
Edwards
³

et al. 2018
Phys. Rev. D