Caloric curve for quasiprojectile (QP) particles is investigated, using the INDRA data set of $\mathrm{Xe}+\mathrm{Sn}$ at 50 MeV/u. A constant pressure condition is applied, approximated by the isotropic expansion of the QP source with a constant velocity, but neither limiting temperature nor backbending behavior is observed in the extracted caloric curves. The extracted caloric curves follow a theoretical curve from the Fermi gas model with a level density parameter of $a=13$. ${}^3\mathrm{He}$ and $\alpha$ particles show much higher temperature values than those of the Hydrogen isotopes. The dynamical origin of the high energy light charged particles in the QP source is investigated and it is found that they are associated with the intermediate mass fragment production at the midrapidity in midperipheral to peripheral collisions. This component likely washes away the characteristic features of the liquid-gas phase transition, such as limiting temperature and backbending behaviors, in the caloric curves extracted in this study.

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• Heavy-particle decays
• Liquid-gas phase transition
• Low & intermediate energy heavy-ion reactions
• Transition temperature