Europhys. Lett.
Volume 75, Number 1, July 2006
Page(s) 36 - 41
Section Nuclear physics
Published online 09 June 2006
Europhys. Lett., 75 (1), pp. 36-41 (2006)
DOI: 10.1209/epl/i2006-10083-y

The hyperon mean free paths in the relativistic mean field

Q. L. Wang, L. Dang, X. H. Zhong, C. Y. Song and P. Z. Ning

Department of Physics, Nankai University - Tianjin 300071, PRC

received 17 February 2006; accepted in final form 17 May 2006
published online 9 June 2006

The $\Lambda$- and $\Xi^-$-hyperon mean free paths in finite nuclei are firstly calculated in the relativistic mean-field theory. The real optical potentials are derived from the RMF approach, while the imaginary parts are obtained from the assumptions: $U^{\mathrm{IY}}_{\mathrm{S}} = \alpha_{\sigma \mathrm{Y}}\cdot
U_{\mathrm{S}}^{\mathrm{IN}}$ and $U^{\mathrm{IY}}_{\mathrm{V}} =
\alpha_{\omega \mathrm{Y}}\cdot U_{\mathrm{V}}^{\mathrm{IN}}$. With these assumptions, the depth of the imaginary potential for $\Xi^-$ is $W_{\Xi}\simeq -3.5\un{MeV}$, and for $\Lambda$ is $W_{\Lambda}\simeq -7\un{MeV}$ at low incident energy. We find that the hyperon MFP decreases with the increment of the incident energies of the hyperon (from $200\un{MeV}$ to $800\un{MeV}$); and in the nuclear interior, the MFP is about 2-$3\un{fm}$ for $\Lambda$, and about 4-$8\un{fm}$ for $\Xi^-$, depending on the incident energy of the hyperon.

21.65.+f - Nuclear matter.
21.30.Fe - Forces in hadronic systems and effective interactions.

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