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arXiv · 1605.03993

Rho resonance parameters from lattice QCD

Dehua Guo·Andrei Alexandru·Raquel Molina·Michael Doering
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Abstract

We perform a high-precision calculation of the phase shifts for $\pi$-$\pi$ scattering in the I = 1, J = 1 channel in the elastic region using elongated lattices with two mass-degenerate quark favors ($N_f = 2$). We extract the $\rho$ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to $m_{\pi} = 226$MeV and $m_{\pi} = 315$MeV, and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase-shifts around the resonance for both quark masses. We find that the extrapolated value, $m_{\rho} = 720(1)(15)$MeV, is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

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Dehua Guo, Andrei Alexandru, Raquel Molina, Michael Doering. 2016-05-12. Rho resonance parameters from lattice QCD. https://doi.org/10.1103/physrevd.94.034501

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