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arXiv · 1110.3918

Lattice QCD calculation of $ππ$ scattering length

Ziwen Fu
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Abstract

We study s-wave pion-pion ($ππ$) scattering length in lattice QCD for pion masses ranging from 330 MeV to 466 MeV. In the "Asqtad" improved staggered fermion formulation, we calculate the $ππ$ four-point functions for isospin I=0 and 2 channels, and use chiral perturbation theory at next-to-leading order to extrapolate our simulation results. Extrapolating to the physical pion mass gives the scattering lengths as $m_πa_0^{I=2} = -0.0416(2)$ and $m_πa_0^{I=0} = 0.186(2)$ for isospin I=2 and 0 channels, respectively. Our lattice simulation for $ππ$ scattering length in the I=0 channel is an exploratory study, where we include the disconnected contribution, and our preliminary result is near to its experimental value. These simulations are performed with MILC 2+1 flavor gauge configurations at lattice spacing $a \approx 0.15$ fm.

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Ziwen Fu. 2012-06-17. Lattice QCD calculation of $ππ$ scattering length. https://doi.org/10.1088/0253-6102%2F57%2F1%2F13

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