We determined scattering length and effective range of ΛΛ scattering for the ΛΛ relative energy (MΛΛ-2MΛ) from ΛΛ threshold to 30 MeV/c2. Phase shift of the ΛΛ wave function which described by scattering length and effective range was determined by fitting the ΛΛ mass spectrum. The obtained scattering length -0.10+1.37-1.56± 0.04, and effective range 13.90+0.37-9.13± 10.53, fm is the most consistent with the values predicted by using a series of the Nijmegen soft core models NSC97's. However the predicted values by using the Nijmegen hard core model ND (G-matrix), the extended soft core model ESC00, and the Kyoto-Niigata FSS are out of three standard deviations from the determined scattering parameters. Further, we determine ΛΛ potential by fitting the ΛΛ invariant mass spectrum using numerically solved ΛΛ wave function with two-Gaussian shaped potential well. The ΛΛ scattering parameters derived from the wave function are found to be scattering length -0.09, and effective range 29.34 fm with a maximum hase shift of 2.4 deg.
- Effective range
- Scattering length