Color Anomaly and Flavor-Singlet Axial Charge of the Proton in the Chiral Bag: The Cheshire Cat Revisited

Mannque Rho; Vicente Vento

doi:10.1016/s0375-9474(97)80698-7

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arXiv · hep-ph/9704328

Color Anomaly and Flavor-Singlet Axial Charge of the Proton in the Chiral Bag: The Cheshire Cat Revisited

Mannque Rho·Vicente Vento

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Abstract

Quantum effects inside the chiral bag induce a color anomaly which requires a compensating surface term to prevent breakdown of color gauge invariance. We show that the presence of this surface term first discovered several years ago allows one to derive in a gauge-invariant way a chiral-bag version of the Shore-Veneziano two-component formula for the flavor-singlet axial charge of the proton. This has relevance to what is referred to as the ``proton spin problem" on the one hand and to the Cheshire-Cat phenomenon in hadron structure on the other. We show that when calculated to the leading order in the color gauge coupling and for a specific color electric monopole configuration in the bag, one can obtain a striking Cheshire-Cat phenomenon with a negligibly small singlet axial charge.

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Mannque Rho, Vicente Vento. 1997-04-15. Color Anomaly and Flavor-Singlet Axial Charge of the Proton in the Chiral Bag: The Cheshire Cat Revisited. https://doi.org/10.1016/s0375-9474(97)80698-7

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