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arXiv · 1010.4148

m_pi and N_c dependence of resonances from Unitarized Chiral Perturbation Theory

G. Rios·C. Hanhart·J. R. Pelaez
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Abstract

We review our studies on the rho and sigma resonances properties derived from the Inverse Amplitude Method. In particular, we study the leading $1/N_c$ behavior of the resonances masses and widths and their evolution with changing $m_π$. The $1/N_c$ expansion gives a clear definition of $\bar qq$ states, which is neatly satisfied by the $ρ$ but not by the sigma, showing that its dominant component is not $\bar qq$. The $m_π$ dependence of the resonance properties is relevant to connect with lattice studies. We show that our predictions compare well with some lattice results and we find that the rho-pi-pi coupling constant is $m_π$ independent, in contrast with the sigma-pi-pi$ coupling, that shows a strong $m_π$ dependence.

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G. Rios, C. Hanhart, J. R. Pelaez. 2010-10-25. m_pi and N_c dependence of resonances from Unitarized Chiral Perturbation Theory. https://doi.org/10.1063/1.3647171

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