# Pion Freeze-Out Time in Pb+Pb Collisions at 158 A GeV/c Studied via $\pi^-/\pi^+$ and $K^-/K^+$ Ratios

Abstract : The effect of the final state Coulomb interaction on particles produced in Pb+Pb collisions at 158 A GeV/c has been investigated in the WA98 experiment through the study of the pi-/pi+ and K-/K+ ratios measured as a function of transverse mass. While the ratio for kaons shows no significant transverse mass dependence, the pi-/pi+ ratio is enhanced at small transverse mass values with an enhancement that increases with centrality. A silicon pad detector located near the target is used to estimate the contribution of hyperon decays to the pi-/pi+ ratio. The comparison of results with predictions of the RQMD model in which the Coulomb interaction has been incorporated allows to place constraints on the time of the pion freeze-out.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00238256
Contributor : Dominique Girod <>
Submitted on : Monday, February 4, 2008 - 2:07:03 PM
Last modification on : Sunday, January 3, 2021 - 8:58:01 AM

### Citation

M.M. Aggarwal, Z. Ahammed, A.L.S. Angelis, V. Antonenko, V. Arefiev, et al.. Pion Freeze-Out Time in Pb+Pb Collisions at 158 A GeV/c Studied via $\pi^-/\pi^+$ and $K^-/K^+$ Ratios. European Physical Journal C: Particles and Fields, Springer Verlag (Germany), 2006, 48, pp.343-352. ⟨10.1140/epjc/s10052-006-0081-x⟩. ⟨in2p3-00238256⟩

Record views