Spontaneous symmetry breaking in superfluid helium-4

We derive an analytical expression for a critical temperature of spontaneous symmetry breaking in a repulsive hard-core interacting Bose system. We show that the critical temperature of spontaneous symmetry breaking in a hard-core interacting Bose system is determined by the three physical parameters: the density of Bose liquid at absolute zero (ρ0ρ0), the mass (m) and the hard sphere diameter (σ  ) of a boson. The formula that we have derived is Tc=ρ0πℏ2σ/m2kBTc=ρ0πℏ2σ/m2kB. We report TcTc of liquid helium-4 is 2.194 K, which is significantly close to the λ-temperature of 2.1768 K. The deviation between the predicted and experimental values of the λ-temperature is less than 1%.