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Off-shell pions in Boltzmann-Uehling-Uhlenbeck transport theory

A. B. Larionov·U. Mosel
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Abstract

Due to large pi N --> Delta cross section a pion acquires a large width in nuclear matter. Therefore, a Delta-resonance decaying in the nuclear medium can produce far off-shell pions, which will gradually lose their virtuality while propagating to the vacuum. To describe such off-shell dynamics, we implemented a pion spectral function for finite nuclear matter density -- calculated on the basis of the Delta-hole model -- in the BUU transport approach. The pion off-shell dynamics leads to an enhancement of the low-p_t pion yields in the collisions of Au+Au at 1 A GeV.

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A. B. Larionov, U. Mosel. 2002-07-24. Off-shell pions in Boltzmann-Uehling-Uhlenbeck transport theory. https://doi.org/10.1103/physrevc.66.034902

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