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arXiv · 0804.2108

On the determination of $σ$ from experimental data on the $ππ$ isoscalar $S$-wave at low energies

Irinel Caprini
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Abstract

We investigate the determination of the pole associated to $σ$ from $ππ$ scattering data below the $K\bar{K}$ threshold, including the new precise data from $K_{e4}$ decay reported recently by the NA48/2 Collaboration. Using a large class of analytic parametrizations based on expansions in powers of conformal variables, we obtain for the mass and width of $σ$ values which are consistent with those calculated recently using ChPT and Roy equations, but have larger theoretical uncertainties.

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Irinel Caprini. 2008-04-14. On the determination of $σ$ from experimental data on the $ππ$ isoscalar $S$-wave at low energies. https://doi.org/10.1063/1.2973503

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