Speaker
Pablo Sanchez Puertas
(Johannes Gutenberg University, Mainz)
Description
Pseudoscalar-meson decays (π0, η, η ) into lepton pairs (e+e−, µ+µ−) are unique in its kind as they probe the neutral pseudoscalar meson structure in the whole energy-range. This structure, which is encoded in the doubly virtual transition form factor (TFF) governing their interactions with two photons, needs a complete energy description. In this work, we identify the relevant energy regimes related to this processes and propose the use of rational approximants for describing the TFF, emphasizing the correct low- energy description and high-energy implementation. Motivated by the range spanned by the pseudoscalar masses, we will discuss the use of different rational approximants: Pade' approximants, which have been successfully used in the past [1,2], its necessary extension to their bivariate version (Canterbury approximants) [3] , and, as a novel approach, Quadratic approximants [4], which are very interesting, specially, for the η case. Finally, we calculate the branching ratios for the different processes and estimate the different uncertainties, highlighting possible future experiments that may improve our description.
References
1. P. Masjuan, Phys. Rev. D 86, 094021 (2012).
2. R. Escribano, P. Masjuan, and P. Sanchez-Puertas, Phys. Rev. D 89, 034014, (2014).
3. P. Masjuan, and P. Sanchez-Puertas, In preparation.
2. S. Gonzalez-Solis, P. Masjuan, and P. Sanchez-Puertas, In preparation.
Primary author
Pablo Sanchez Puertas
(Johannes Gutenberg University, Mainz)
Co-author
Pere Masjuan
(Johannes Gutenberg-Universität Mainz, Institute für Kernphysik)
