Charge radius of neutron deficient $^{\mathrm{54}}$Ni and constraints on slope parameter $L$ in the neutron equation of state*

The charge radius of $^{\mathrm{54}}$Ni was determined using collinear laser spectroscopy at the BEam COoling and LAser spectroscopy facility. The $^{\mathrm{54}}$Ni radius is critical to determine the slope $L$ of symmetry energy in the nuclear equation of state. The linear correlation between the difference of charge radii of mirror nuclei $\Delta R_{mirr}$ and $L$ is used to set constraint on $L$ using the charge radii of proposed $^{\mathrm{54}}$Ni and its mirror partner $^{\mathrm{54}}$Fe, whose radius is also known. Details of the experiment and the progress of data analysis will be discussed.