Abstract
We provide the complete set of radiative corrections to the Dalitz decays $\eta^{(\prime)}\to \ell^+\ell^-\gamma$ beyond the soft-photon approximation, i.e. over the whole range of the Dalitz plot and with no restrictions on the energy of a radiative photon. The corrections inevitably depend on the $\eta^{(\prime)}\to\gamma^*\gamma^{(*)}$ transition form factors. For the singly virtual transition form factor appearing e.g. in the bremsstrahlung correction, recent dispersive calculations are used. For the one-photon-irreducible contribution at the one-loop level (for the doubly virtual form factor), we use a vector-meson-dominance-inspired model while taking into account the $\eta$-$\eta^\prime$ mixing.
Highlights
AND SUMMARYLooking for effects of new physics is certainly one of the major contemporary goals of particle physics
The simplest physically relevant model we can imagine is based on the vector-meson dominance (VMD) scenario, i.e., an ansatz which assumes that the form factor is saturated by the lowest-lying multiplet of vector mesons
The vector currents related to physical states of ω, ρ0, and φ mesons are identical to the basis currents
Summary
Looking for effects of new physics is certainly one of the major contemporary goals of particle physics. To the leading-order (LO) decay width, in the case of the bremsstrahlung correction the singly virtual transition form factor appears The calculation of this contribution includes integration over angles and energies of the bremsstrahlung photon. As in the pion case, radiative corrections for these processes are crucial in order to extract relevant information from the data This goes together with the fact that currently an ambitious experimental ηð0Þ program aiming for an accuracy never reached before is running, for instance, at the experiments BES-III [8], A2 [9], and GlueX [10]. [6], which was related to the case of the η → eþe−γ decay, we take into account muon loops and hadronic corrections as a part of the vacuum polarization contribution, 1γIR contribution, higher-order final-state lepton mass correction, and form-factor effects.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
