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arXiv · hep-ph/0009206

pi(-)p atom in ChPT: strong energy-level shift

V. E. Lyubovitskij·A. Rusetsky
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Abstract

The general formula of the pi(-)p atom strong energy-level shift in the 1s state is derived in the next-to-leading order in the isospin breaking, and in all orders in chiral expansion. Isospin-breaking corrections to the level shift are explicitly evaluated at order p^2 in ChPT. The results clearly demonstrate the necessity to critically reaccess the values of the piN scattering lengths, extracted from the energy-level shift measurement by means of the potential model-based theoretical analysis.

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V. E. Lyubovitskij, A. Rusetsky. 2000-09-18. pi(-)p atom in ChPT: strong energy-level shift. https://doi.org/10.1016/s0370-2693(00)01185-0

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