η′ → π0γγ and η′ → ηγγ: a primer analysis
Grup de Física Teòrica (Departament de Física) and Institut de Física d’Altes Energies (IFAE), Universitat Autònoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain
a e-mail: firstname.lastname@example.org
The electromagnetic rare decays η′ → π0γγ and η′ → π0γγ are analysed for the first time and their predicted branching ratios given. The vector meson exchange dominant contribution is treated using Vector Meson Dominance and the scalar component is estimated by means of the Linear Sigma Model. The agreement between our calculation and the measurement of the related process η → π0γγ is a check of the procedure. Scalar meson effects are seen to be irrelevant for η′ → π0γγ, while a significant scalar contribution due to the σ(500) resonance seems to emerge in the case of η′ → π0γγ. Future measurements coming from KLOE-2, Crystal Ball, WASA, and BES-III will elucidate if any of these processes carry an important scalar contribution or they are simply driven by the exchange of vector mesons.
© Owned by the authors, published by EDP Sciences, 2012
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.