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arXiv · 2602.18378

On the simulated kinematic distributions of heavy meson decays

Florian Herren·Raynette van Tonder
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Abstract

Modern measurements in flavour physics rely on accurate simulations of signal and background processes, provided by a wide range of general-purpose and specialised Monte-Carlo event generators. Due to the inclusion of a larger amount of specialised decays of heavy hadrons, EvtGen is often the tool of choice for many scenarios. We investigate the phase-space sampling algorithm of EvtGen and demonstrate that it generates unphysical features in kinematic distributions of semileptonic $B$ decays involving resonances, originating from neglected phase-space factors. We provide a short-term solution to correct the affected simulated samples through reweighting of the hadronic invariant mass distribution.

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Florian Herren, Raynette van Tonder. 2026-02-20. On the simulated kinematic distributions of heavy meson decays. https://doi.org/10.21468/scipostphys.20.6.161

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