@Article{Fischer_etal2021,
author="Fischer, M.
and Kostrzewa, B.
and Liu, L. M.
and Romero-Lopez, F.
and Ueding, M.
and Urbach, C.",
title="Scattering of two and three physical pions at maximal isospin from lattice QCD Extended Twisted Mass Collaboration",
journal="European Physical Journal C",
year="2021",
publisher="Springer",
volume="81",
number="5",
pages="436 - 19pp",
abstract="We present the first direct N-f = 2 lattice QCD computation of two- and three-pi(+) scattering quantities that includes an ensemble at the physical point. We study the quark mass dependence of the two-pion phase shift, and the three-particle interaction parameters. We also compare to phenomenology and chiral perturbation theory (ChPT). In the two-particle sector, we observe good agreement to the phenomenological fits in s- and d-wave, and obtain M(pi)a(0) = -0.0481(86) at the physical point from a direct computation. In the three-particle sector, we observe reasonable agreement at threshold to the leading order chiral expansion, i.e. a mildly attractive three-particle contact term. In contrast, we observe that the energy-dependent part of the three-particle quasilocal scattering quantity is not well described by leading order ChPT.",
optnote="WOS:000680425500003",
optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4900), last updated on Wed, 11 Aug 2021 09:00:48 +0000",
issn="1434-6044",
doi="10.1140/epjc/s10052-021-09206-5",
opturl="https://arxiv.org/abs/2008.03035",
opturl="https://doi.org/10.1140/epjc/s10052-021-09206-5",
language="English"
}