Ratios of differential chemical potential values relative to the temperature, $({\mu }_n-{\mu }_p)/T$, extracted from isotope yields of 13 reaction systems at 40 MeV/nucleon are compared to those of a quantum statistical model to determine the temperature and symmetry energy values of the fragmenting system. The experimental $({\mu }_n-{\mu }_p)/T$ values are extracted based on the modified Fisher model. Using the density value of $\rho /{\rho }_0=0.56$ from the previous analysis, the temperature and symmetry energy values of $T=4.6\pm 0.4$ MeV and $a_{\mathrm{sym}}=23.6\pm 2.1$ MeV are extracted in a framework of a quantum statistical model. These values agree well with those of the previous work, in which a self-consistent method was utilized with antisymmetrized molecular dynamics simulations. The extracted temperature and symmetry energies are discussed together with other experimental values published in literature.

• Received 15 September 2015
• Revised 29 January 2017

DOI:https://doi.org/10.1103/PhysRevC.95.044601