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Sum rule for the backward spin polarizability of the nucleon from a backward dispersion relation

A. I. L'vov·A. M. Nathan
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Abstract

A new sum rule for $γ_π$, the backward spin polarizability of the nucleon, is derived from a backward-angle dispersion relation. Taking into account single- and multi-pion photoproduction in the s-channel up to the energy 1.5 GeV and resonances in the t-channel with mass below 1.5 GeV, it is found for the proton and neutron that $[γ_π]_p$ = -39.5 +/- 2.4 and $[γ_π]_n$ = 52.5 +/- 2.4, respectively, in units of 10^{-4} fm^4.

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A. I. L'vov, A. M. Nathan. 1998-07-09. Sum rule for the backward spin polarizability of the nucleon from a backward dispersion relation. https://doi.org/10.1103/physrevc.59.1064

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