The γ^∗γ^∗ → η_c(1S,2S) transition form factors for two spacelike photons

Summary, in English

We discuss γ^∗γ^∗ → η_c(1S), η_c(2S) transition form factors for both virtual photons. The general formula is given. We use different models for the cc¯ wave function obtained from the solution of the Schrödinger equation for different cc¯ potentials: harmonic oscillator, Cornell, logarithmic, power-law, Coulomb and Buchmüller-Tye. We showed some examples of wave functions in the Light Front representation as well as in the rest frame of cc¯ pair. We compare our results to the BaBar experimental data for η_c(1S), for one real and one virtual photon, and to the values collected by the Particle Data Group for F(0,0), decay width Γ_γγ and decay constant f_ηc. We also considered the non-relativistic limit for F(0,0) form factor with the wave function at the origin R(0).

• Author: Izabela Babiarz; Victor P. Goncalves; Roman Pasechnik; Wolfgang Schäfer; Antoni Szczurek
• Department/s: Theoretical Particle Physics - Has been reorganised
• Publishing year: 2019
• Language: English
• Publication/Series: Proceedings of Science
• Volume: 364
• Links: http://dx.doi.org/10.22323/1.364.0467
• Document type: Conference paper
• Topic: Subatomic Physics
• Conference name: 2019 European Physical Society Conference on High Energy Physics, EPS-HEP 2019
• Conference date: 2019-07-10 - 2019-07-17
• Conference place: Ghent, Belgium
• Status: Published
• ISBN/ISSN/Other: ISSN: 1824-8039