  We study the chemical potential effects on the chiral phase transition in a
simply improved soft-wall AdS/QCD model, which can realize consistently the
properties of linear confinement and spontaneous chiral symmetry breaking. The
$\mu-T$ phase diagrams with both zero and physical quark masses have been
obtained from this model. For the case of physical quark mass, the chiral
transition has a crossover behavior at low chemical potential. With the
increase of the chemical potential $\mu$, the critical temperature $T_c$
descends towards zero, and the crossover transition turns into a first-order
one at some intermediate value of $\mu$, which implies that a critical end
point naturally exists in this improved soft-wall model. All these features
agree with our current perspective on the QCD phase diagram.

High Energy Physics - Phenomenology