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arXiv · 1108.5980

Mass dependence of pion-pion phase shifts within standard and unitarized ChPT versus Lattice results

J. Nebreda·J. R. Pelaez·G. Rios
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Abstract

We report on our recent results in the study of the chiral extrapolation of the phase-shifts in elastic pion-pion scattering, using both standard and unitarized ChPT to one and two loops. In the standard ChPT approach, limited to low momenta, we study the S, P and D waves. Unitarization extends the analysis to energies of around 1 GeV, being compatible with standard ChPT at low energies for the S and P waves. We then compare with lattice results and find a good agreement of standard ChPT below p \sim 200 MeV for the I=2, J=0 and I=1, J=1 channels and up to p \sim 500 MeV for the I=2, J=2 channel. Unitarized ChPT improves the agreement in the scalar and vector channels at higher energies. We have also performed a Montecarlo analysis to provide an estimation of the uncertainties.

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J. Nebreda, J. R. Pelaez, G. Rios. 2011-08-30. Mass dependence of pion-pion phase shifts within standard and unitarized ChPT versus Lattice results. https://arxiv.org/abs/1108.5980

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