S-wave meson-baryon potentials with strangeness from Lattice QCD

Abstract Employing an all-to-all quark propagator technique, we investigate kaon–nucleon interactions in lattice QCD. We calculate the S-wave kaon–nucleon potentials at the leading order in the derivative expansion in the time-dependent HAL QCD method, using (2+1)-flavor gauge configurations on $32^3 \times 64$ lattices with lattice spacing $a \approx 0.09$ fm and pion mass $m_{\pi} \approx 570$ MeV. We take the one-end trick for all-to-all propagators, which allows us to put the zero-momentum hadron operators at both source and sink and to smear quark operators at the source. We find a stronger repulsive interaction in the $I=1$ channel than in the $I=0$. The phase shifts obtained by solving the Schrödinger equations with the potentials qualitatively reproduce the energy dependence of the experimental phase shifts, and have similar behavior to previous results from lattice QCD without all-to-all propagators. Our study demonstrates that the all-to-all quark propagator technique with the one-end trick is useful for studying interactions in meson–baryon systems in the HAL QCD method, so we will apply it to meson–baryon systems which contain quark–antiquark creation/annihilation processes in our future studies.

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S-wave \pi K scattering length from lattice QCD

10.22323/1.091.0098 ◽

2010 ◽

Author(s):

K. Sasaki

Keyword(s):

Lattice Qcd ◽

Scattering Length ◽

S Wave

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Nπ scattering in the Roper channel

EPJ Web of Conferences ◽

10.1051/epjconf/201817505004 ◽

2018 ◽

Vol 175 ◽

pp. 05004

Author(s):

M. Padmanath ◽

C. B. Lang ◽

Luka Leskovec ◽

Sasa Prelovsek

Keyword(s):

Lattice Qcd ◽

Positive Parity ◽

Roper Resonance ◽

S Wave ◽

Lattice Spectrum ◽

Lattice Calculations ◽

Channel Effects ◽

Technical Details ◽

Elastic Approximation ◽

Coupled Channel

We present results from our recent lattice QCD study of Nπ scattering in the positive-parity nucleon channel, where the puzzling Roper resonance N*(1440) resides in experiment. Using a variety of hadron operators, that include qqq-like, Nπ in p-wave and Nσ in s-wave, we systematically extract the excited lattice spectrum in the nucleon channel up to 1.65 GeV. Our lattice results indicate that Nπ scattering in the elastic approximation alone does not describe a low-lying Roper. Coupled channel effects between Nπ and Nππ seem to be crucial to render a low-lying Roper in experiment, reinforcing the notion that this state could be a dynamically generated resonance. After giving a brief motivation for studying the Roper channel and the relevant technical details to this study, we will discuss the results and the conclusions based on our lattice investigation and in comparison with other lattice calculations.

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