RT Journal Article
T1 Η → π⁰ ϒ ϒ decay within a chiral unitary approachη
A1 Oset, E.
A1 Peláez Sagredo, José Ramón
A1 Roca, L.
AB We improve the calculations of the η→π⁰ϒϒ  decay within the context of meson chiral Lagrangians. We                                                                                                                use a chiral unitary approach for the meson-meson interaction, thus generating the a₀(980) resonance and fixing the long standing sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes, first, by using vector meson dominance couplings normalized to agree with radiative vector meson decays and, second, by checking the consistency of the calculations with the related ϒ ϒ → π⁰η reaction. We find an η→π⁰ ϒϒ decay width of 0.47 ± 0.10 eV, in clear disagreement with published data but in remarkable agreement with the most recent measurement.
PB Amer Physical Soc
SN 0556-2821
YR 2003
FD 2003-04
LK https://hdl.handle.net/20.500.14352/51740
UL https://hdl.handle.net/20.500.14352/51740
LA eng
NO ©2003 The American Physical Society.We are especially grateful to J.A. Oller for fruitful discussions, technical help, and his careful reading of the manuscript. We would also like to acknowledge useful discussions with J. Bijnens. One of us, L.R., acknowledges support from the Consejo Superior de Investigaciones Científicas. J.R.P. acknowledges financial support from a CICYT-INFN collaboration grant as well as a Marie Curie fellowship under contract MCFI-2001-01155. He also thanks the Dipartimento di Fisica, Universita’ di Firenze, and INFN, Sezione di Firenze, for its hospitality. This work is also partly supported by DGICYT contract numbers BFM2000-1326, PB98-0782, and the E.U. EURIDICE network contract no. HPRN-CT- 2002-00311 2002-00311.
NO Consejo Superior de Investigaciones Científicas
NO CICYT-INFN
NO Marie Curie fellowship
NO DGICYT, Spain
NO E.U. EURIDICE network
DS Docta Complutense
RD 29 abr 2025