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arXiv · 2307.13471

Lattice QCD study of $\pi\Sigma-\bar{K}N$ scattering and the $\Lambda(1405)$ resonance

John Bulava·Bárbara Cid-Mora·Andrew D. Hanlon·Ben Hörz·Daniel Mohler·Colin Morningstar·Joseph Moscoso·Amy Nicholson·Fernando Romero-López·Sarah Skinner·André Walker-Loud
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Abstract

A lattice QCD computation of the coupled channel $\pi\Sigma-\bar{K}N$ scattering amplitudes in the $\Lambda(1405)$ region is detailed. Results are obtained using a single ensemble of gauge field configurations with $N_{\rm f} = 2+1$ dynamical quark flavors and $m_{\pi} \approx 200$ MeV and $m_K\approx487$ MeV. Hermitian correlation matrices using both single baryon and meson-baryon interpolating operators for a variety of different total momenta and irreducible representations are used. Several parametrizations of the two-channel scattering $K$-matrix are utilized to obtain the scattering amplitudes from the finite-volume spectrum. The amplitudes, continued to the complex energy plane, exhibit a virtual bound state below the $\pi\Sigma$ threshold and a resonance pole just below the $\bar{K}N$ threshold.

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John Bulava, Bárbara Cid-Mora, Andrew D. Hanlon, Ben Hörz, Daniel Mohler, Colin Morningstar, Joseph Moscoso, Amy Nicholson, Fernando Romero-López, Sarah Skinner, André Walker-Loud. 2023-07-25. Lattice QCD study of $\pi\Sigma-\bar{K}N$ scattering and the $\Lambda(1405)$ resonance. https://doi.org/10.1103/physrevd.109.014511

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