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arXiv · hep-ph/9705380

Improved determination of the classical sphaleron transition rate

J. Ambjorn·A. Krasnitz
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Abstract

We determine the sphaleron transition rate using real time lattice simulations of the classical system. An improved definition of the lattice topological charge allows us to obtain a more reliable estimate of the transition rate. For an SU(2) Yang-Mills-Higgs system in the broken phase we find the transition rate to be strongly suppressed, and we have observed no sphaleron transitions in the range of coupling constants used. For a pure SU(2) Yang-Mills system in large volumes the rate behaves as $κ(α_w T)^4$, with $κ$ slightly decreasing as the lattice spacing is reduced. If the lattice size is reduced to about twice the magnetic screening length, the rate is suppressed by finite-size effects, and $κ$ is approximately proportional to the lattice spacing. Our rate measurements are supplemented by analysis of gauge field correlation functions in the Coulomb gauge.

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J. Ambjorn, A. Krasnitz. 1997-05-21. Improved determination of the classical sphaleron transition rate. https://doi.org/10.1016/s0550-3213(97)00524-5

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