dorsal/arxiv
View SchemaHow sensitive are various NN observables to changes in the $\pi NN$ coupling constant?
| Authors | R. Machleidt |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/9909036 |
| URL | https://arxiv.org/abs/nucl-th/9909036 |
| DOI | 10.1238/Physica.Topical.087a00047 |
| Journal | Phys.Scripta T87:47-52,2000 |
Abstract
The deuteron, NN analyzing powers A_y, and the singlet scattering length show great sensitivity to the $\pi NN$ coupling constant $g_\pi$. While the pp A_y data favor $g^2_\pi/4\pi\leq 13.6$, the np A_y data and the deuteron quadrupole moment imply $g^2_\pi/4\pi\geq 14.0$. The two diverging values could be reconciled by the assumption of (substantial) charge-splitting of $g_\pi$. However, the established theoretical explanation of the charge-dependence of the $^1S_0$ scattering length (based upon pion mass splitting) is very sensitive to a difference between $g_{\pi^0}$ and $g_{\pi^\pm}$ and rules out any substantial charge-splitting of $g_\pi$. Thus, there are real and large discrepancies between the values for $g_\pi$ extracted from different NN observables. Future work that could resolve the problems is suggested.
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"abstract": "The deuteron, NN analyzing powers A_y, and the singlet scattering length show\ngreat sensitivity to the $\\pi NN$ coupling constant $g_\\pi$. While the pp A_y\ndata favor $g^2_\\pi/4\\pi\\leq 13.6$, the np A_y data and the deuteron quadrupole\nmoment imply $g^2_\\pi/4\\pi\\geq 14.0$. The two diverging values could be\nreconciled by the assumption of (substantial) charge-splitting of $g_\\pi$.\nHowever, the established theoretical explanation of the charge-dependence of\nthe $^1S_0$ scattering length (based upon pion mass splitting) is very\nsensitive to a difference between $g_{\\pi^0}$ and $g_{\\pi^\\pm}$ and rules out\nany substantial charge-splitting of $g_\\pi$. Thus, there are real and large\ndiscrepancies between the values for $g_\\pi$ extracted from different NN\nobservables. Future work that could resolve the problems is suggested.",
"arxiv_id": "nucl-th/9909036",
"authors": [
"R. Machleidt"
],
"categories": [
"nucl-th"
],
"doi": "10.1238/Physica.Topical.087a00047",
"journal_ref": "Phys.Scripta T87:47-52,2000",
"title": "How sensitive are various NN observables to changes in the $\\pi NN$ coupling constant?",
"url": "https://arxiv.org/abs/nucl-th/9909036"
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