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Freeze-Out Time in Ultrarelativistic Heavy Ion Collisions from Coulomb Effects in Transverse Pion Spectra

H. W. Barz·J. P. Bondorf·J. J. Gaardhøje·H. Heiselberg
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Abstract

The influence of the nuclear Coulomb field on transverse spectra of $π^+$ and $π^-$ measured in $Pb+Pb$ reactions at 158 A GeV has been investigated. Pion trajectories are calculated in the field of an expanding fireball. The observed enhancement of the $π^-/π^+$ ratio at small momenta depends on the temperature and transverse expansion velocity of the source, the rapidity distribution of the net positive charge, and mainly the time of the freeze-out.

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H. W. Barz, J. P. Bondorf, J. J. Gaardhøje, H. Heiselberg. 1997-04-22. Freeze-Out Time in Ultrarelativistic Heavy Ion Collisions from Coulomb Effects in Transverse Pion Spectra. https://doi.org/10.1103/physrevc.56.1553

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