Meson-baryon scattering lengths without annihilation diagrams to order $p^4$ in heavy baryon chiral perturbation theory

Fuente: arXiv
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Main Authors: Ou-Yang, Jing, Wang, Ke, Huang, Bo-Lin
Format: Preprint
Published: 2025
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author Ou-Yang, Jing
Wang, Ke
Huang, Bo-Lin
author_facet Ou-Yang, Jing
Wang, Ke
Huang, Bo-Lin
contents We calculate the threshold $T$ matrices of the meson and baryon processes that have no annihilation diagrams: $π^{+}Σ^{+}$, $π^{+}Ξ^0$, $K^+p$, $K^+n$, and $\bar{K}^0Ξ^0$ to the fourth order in heavy baryon chiral perturbation theory. By performing least squares and Bayesian fits to the non-physical lattice QCD data, we determine the low-energy constants through both perturbative and non-perturbative iterative methods. By using these low-energy constants, we obtain the physical scattering lengths in these fits. The convergence behavior is not good across all channels in the perturbative method. The scattering lengths for the five channels, obtained by taking the median values from four different fitting approaches, are $a_{π^+Σ^+}=-0.16\pm 0.07\,\text{fm}$, $a_{π^+Ξ^0}=-0.04\pm0.04\,\text{fm}$, $a_{K^+p}=-0.41\pm 0.11\,\text{fm}$, $a_{K^+n}=-0.19\pm 0.10\,\text{fm}$, and $a_{\bar{K}^0Ξ^0}=-0.30\pm 0.07\,\text{fm}$, where the uncertainties are conservatively estimated by taking the maximum deviation between the median and extreme values of the statistical errors.
format Preprint
id arxiv_https___arxiv_org_abs_2506_22339
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Meson-baryon scattering lengths without annihilation diagrams to order $p^4$ in heavy baryon chiral perturbation theory
Ou-Yang, Jing
Wang, Ke
Huang, Bo-Lin
High Energy Physics - Phenomenology
High Energy Physics - Lattice
Nuclear Experiment
Nuclear Theory
We calculate the threshold $T$ matrices of the meson and baryon processes that have no annihilation diagrams: $π^{+}Σ^{+}$, $π^{+}Ξ^0$, $K^+p$, $K^+n$, and $\bar{K}^0Ξ^0$ to the fourth order in heavy baryon chiral perturbation theory. By performing least squares and Bayesian fits to the non-physical lattice QCD data, we determine the low-energy constants through both perturbative and non-perturbative iterative methods. By using these low-energy constants, we obtain the physical scattering lengths in these fits. The convergence behavior is not good across all channels in the perturbative method. The scattering lengths for the five channels, obtained by taking the median values from four different fitting approaches, are $a_{π^+Σ^+}=-0.16\pm 0.07\,\text{fm}$, $a_{π^+Ξ^0}=-0.04\pm0.04\,\text{fm}$, $a_{K^+p}=-0.41\pm 0.11\,\text{fm}$, $a_{K^+n}=-0.19\pm 0.10\,\text{fm}$, and $a_{\bar{K}^0Ξ^0}=-0.30\pm 0.07\,\text{fm}$, where the uncertainties are conservatively estimated by taking the maximum deviation between the median and extreme values of the statistical errors.
title Meson-baryon scattering lengths without annihilation diagrams to order $p^4$ in heavy baryon chiral perturbation theory
topic High Energy Physics - Phenomenology
High Energy Physics - Lattice
Nuclear Experiment
Nuclear Theory
url https://arxiv.org/abs/2506.22339