Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Connecting physical resonant amplitudes and lattice QCD   We present a determination of the isovector, $P$-wave $\pi\pi$ scattering
phase shift obtained by extrapolating recent lattice QCD results from the
Hadron Spectrum Collaboration using $m_\pi =236$ MeV. The finite volume spectra
are described using extensions of L\"uscher's method to determine the infinite
volume Unitarized Chiral Perturbation Theory scattering amplitude. We exploit
the pion mass dependence of this effective theory to obtain the scattering
amplitude at $m_\pi= 140$ MeV. The scattering phase shift is found to be in
good agreement with experiment up to center of mass energies of 1.2 GeV. The
analytic continuation of the scattering amplitude to the complex plane yields a
$\rho$-resonance pole at $E_\rho=
\left[755(2)(1)(^{20}_{02})-\frac{i}{2}\,129(3)(1)(^{7}_{1})\right]~{\rm MeV}$.
The techniques presented illustrate a possible pathway towards connecting
lattice QCD observables of few-body, strongly interacting systems to
experimentally accessible quantities.

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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: astro-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: physics
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The categories of this paper are: nucl-th