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arXiv · 2010.01270

The negative-parity spin-1/2 $Λ$ baryon spectrum from lattice QCD and effective theory

Rafael Pavao·Philipp Gubler·Pedro Fernandez-Soler·Juan Nieves·Makoto Oka·Toru T. Takahashi
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Abstract

The spectrum of the negative-parity spin-1/2 $Λ$ baryons is studied using lattice QCD and hadronic effective theory in a unitarized coupled-channel framework. A direct comparison between the two approaches is possible by considering the hadronic effective theory in a finite volume and with hadron masses and mesonic decay constants that correspond to the situation studied on the lattice. Comparing the energy level spectrum and $SU(3)$ flavor decompositions of the individual states, it is found that the lowest two states extracted from lattice QCD can be identified with one of the two $Λ(1405)$-poles and the $Λ(1670)$ resonance. The quark mass dependences of these two lattice QCD levels are in good agreement with their effective theory counterparts. However, as current lattice QCD studies still rely on three-quark operators to generate the physical states, clear signals corresponding to the meson-baryon scattering states, that appear in the finite volume effective theory calculation, are not yet seen.

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Rafael Pavao, Philipp Gubler, Pedro Fernandez-Soler, Juan Nieves, Makoto Oka, Toru T. Takahashi. 2021-07-19. The negative-parity spin-1/2 $Λ$ baryon spectrum from lattice QCD and effective theory. https://doi.org/10.1016/j.physletb.2021.136473

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