Speaker
Description
The pion vector form factor (VFF) offers the dominant contribution to the hadronic vacuum polarisation (HVP). The lasting tension between modern $e^+e^-$ data calls for a better theoretical understanding of the experimental situation, both in terms of accuracy and precision. To this day, most phenomenologic fits to the pion VFF are performed without explicit modelling of inelastic channels. We present a model based on dispersion relations, that inherently respects the analytic properties of the amplitudes and the unitarity of the S-matrix. The dynamics of the system include s-channel resonance exchange, in addition to background interactions to improve the lineshapes generated from a naive unitarised Gounaris–Sakurai prescription and to simulate non-resonant contributions. The model is fitted to the data from multiple exclusive channels simultaneously.
| Are you an early career researcher? | Yes, a PhD student |
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