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Model-independent effects of Delta excitation in nucleon polarizabilities

Vladimir Pascalutsa·Daniel R. Phillips
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Abstract

Model-independent effects of $Δ$(1232) excitation on nucleon polarizabilities are computed in a Lorentz-invariant fashion. We find a large effect of relative order $(M_Δ- M)/M$ in some of the spin polarizabilities, with the backward spin polarizability receiving the largest contribution. Similar subleading effects are found to be important in the fourth-order spin-independent polarizabilities $α_{Eν}$, $\al_{E2}$, $\be_{Mν}$, and $\be_{M 2}$. Combining our results with those for the model-independent effects of pion loops we obtain predictions for spin and fourth-order polarizabilities which compare favorably with the results of a recent dispersion-relation analysis of data.

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Vladimir Pascalutsa, Daniel R. Phillips. 2003-07-29. Model-independent effects of Delta excitation in nucleon polarizabilities. https://doi.org/10.1103/physrevc.68.055205

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