Two mechanisms for elimination of pinch singularities in out of equilibrium thermal field theories
نویسنده
چکیده
Ill-defined pinch singularities characteristic of out of equilibrium thermal field theories are analyzed. We identify two mechanisms which eliminate pinching: the first is based on the vanishing of phase space at the singular point (Threshold effect). It is effective in QED with massive electron and massless photon. In massless QCD this mechanism fails, but the pinches cancel due to the second mechanism, i.e. due to the spinor/tensor structure of the single self-energy insertion contribution to propagator. The constraints imposed on distribution functions are very reasonable. ∗ E-mail: [email protected]
منابع مشابه
Two mechanisms for the elimination of pinch singularities in out of equilibrium thermal field theories
We analyze ill-defined pinch singularities characteristic of out of equilibrium thermal field theories. We identify two mechanisms that eliminate pinching even at the single selfenergy insertion approximation to the propagator: the first is based on the vanishing of phase space at the singular point (threshold effect). It is effective in QED with a massive electron and a massless photon. In mas...
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