QCD phase diagram at finite isospin chemical potential and temperature in an IR-improved soft-wall AdS/QCD model *

Abstract

Abstract We study the phase transition between the pion condensed phase and normal phase, as well as chiral phase transition in a two flavor ( ) IR- improved soft-wall AdS/QCD model at finite isospin chemical potential and temperature T. By self-consistently solving the equations of motion, we obtain the phase diagram in the plane of and T. The pion condensation appears together with a massless Nambu-Goldstone boson , which is very likely to be a second-order phase transition with mean-field critical exponents in the small region. When , the critical isospin chemical potential approximates to vacuum pion mass . The pion condensed phase exists in an arched area, and the boundary of the chiral crossover intersects the pion condensed phase at a tri-critical point. Qualitatively, the results are in good agreement with previous studies on lattice simulations and model calculations.