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On the vacuum theta angle in Yang-Mills field theories

Liang-Xin Li·Bing-Lin Young
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Abstract

Recently, MIT group found a numerical solution to non-abelian gauge fields which is shown to contain non-integer topological number. Using this fact, V.V.Khoze has argued that the vacuum theta angle is zero. Here, we study this in a complimentary way--its physical respect. The key point is MIT solution has an infinite action. Using this, we prove the vacuum theta angle is zero at semiclassical level.

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Liang-Xin Li, Bing-Lin Young. 1994-05-30. On the vacuum theta angle in Yang-Mills field theories. https://arxiv.org/abs/hep-ph/9405408

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