167 research outputs found
WITHDRAWN: Z+(4430) as a cusp in D∗(2010)D¯1(2420)
No full textThis article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause
A feature of BESIII data for J/Ψ→γ(η′ππ) and comments on η(1405) and η(1475)
No full textAbstractThe X(1835) has been confirmed clearly in new BESIII data for J/Ψ→γ(η′ππ); the angular distribution of the photon is consistent with a pseudoscalar. This makes it a candidate for an ss¯ radial excitation of η′ and η(1440) (or one or both of η(1405) and η(1475)). However, a conspicuous feature of the BESIII data is the absence of evidence for η(1440)→η′ππ while it is well known that η(1440) appears in ηππ. Can these facts be reconciled? There is in fact a simple explanation. The channel η(1440)→ηππ may be explained by the two-step process η(1440)→[K⁎K¯]L=1 and [κK¯]L=0, followed by KK¯→a0(980)→ηπ. This process does not produce any significant η′π signal because of the Adler zero close to the η′π threshold. Some further comments are added on necessary points in fitting data on η(1440)
Comments on the σ and κ
No full textAbstractEvidence for the σ pole has been reported in production processes such as D+→π+π−π+; likewise evidence for the κ pole appears in D+→K−π+π+. Their effects in ππ and Kπ elastic scattering are much less conspicuous. However, consistent fits to both production data and elastic scattering may be obtained by including the Adler zero into an s-dependent width for each resonance. These zeros suppress strongly the effects of the σ and κ poles in elastic scattering; the zeros are absent from amplitudes for production data. With this prescription, data from ππ→ππ, Ke4 decays and CP violation in K0 decays give a σ pole position of (525±40)−i(247±25) MeV. A combined analysis with production data gives a better determination of (533±25)−i(249±25) MeV. The analysis of LASS data for Kπ elastic scattering, including the Adler zero, determines a κ pole at (722±60)−i(386±50) MeV.The Fourier transform of the matrix element for σ→ππ reveals a compact interaction region with RMS radius ∼0.4 fm
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