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arXiv · 1809.06867

A new parametrization for the scalar pion form factors

Stefan Ropertz·Christoph Hanhart·Bastian Kubis
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Abstract

We derive a new parametrization for the scalar pion form factors that allows us to analyze data over a large energy range via the inclusion of resonances, and at the same time to ensure consistency with the high-accuracy dispersive representations available at low energies. As an application the formalism is used to extract resonance properties of excited scalar mesons from data for $\bar B^0_s\to J/ψππ$. In particular we find for the pole positions of $f_0(1500)$ and $f_0(2020)$ $1465\pm 18 - i (50\pm 9)\,\text{MeV}$ and $1910\pm 50 - i(199\pm 40)\,\text{MeV}$, respectively. In addition, from their residues we calculate the respective branching ratios into $ππ$ to be $(58\pm31)\%$ and $(1.3\pm1.8)\%$.

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Stefan Ropertz, Christoph Hanhart, Bastian Kubis. 2018-12-14. A new parametrization for the scalar pion form factors. https://doi.org/10.1140/epjc%2Fs10052-018-6416-6

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