Final state interactions for Bose-Einstein correlations in S+Pb $to$ $pi^+$$pi^+$ +X reaction at energy 200GeV/nucleon

We applied an analytical formula for Bose-Einstein correlations (BEC) developed by us recently to high-energy heavy ion collisions, in particular to data on S+Pb$topi^+$-$pi^+$+X reaction at energy $200$ GeV/nucleon reported by the NA44 Collaboration. It takes into account both Coulomb and strong ($pi$-$pi$~s-wave; I=2) final state interactions (FSI). We have found that inclusion of the strong interaction in addition to Coulomb correction affects significantly the extracted parameters of the BEC like the source size $R$, the degree of coherence $lambda$ and the long-range correlation parameter $gamma$. In particular, the $lambda$ parameter of the BEC is increased by about 20%. Our results differ from those obtained in $e^+e^-$ annihilation in the following way: the $lambda$ parameter does not reach `chaotic limit and the $gamma$ parameter does not approach to zero.