arXiv subjects

Bang-Rong Zhou

Publications and source records attributed to Bang-Rong Zhou.

21 records · Page 2Linked to original sources

arXiv1999

$U_L(N)\times U_R(N)$-invariant four-fermion interactions and Nambu-Goldstone mechanism at finite temperature

In a chiral $U_L(N)\times U_R(N)$ fermion model of NJL-form, we prove that, if all the fermions are assumed to have equal masses and equal chemical potentials, then at the finite temperature $T$ below the symmetry restoration temperature $T_c$, there will be $N^2$ massive scalar composite particles and $N^2$ massless pseudoscalar composite particles (Nambu-Goldstone bosons). This shows that the Goldstone Theorem at finite temperature for spontaneous symmetry breaking $U_L(N)\times U_R(N) \to U_{L+R}(N)$ is consistent with the real-time formalism of thermal field theory in this model.

hep-th↗

arXiv1998

Fermion Self-Energy and Chiral Symmetry Breaking from Four-Fermion and Gauge Interactions

The exact analytic solutions of the linearized Schwinger-Dyson equation of fermion self-energy are used to obtain the effective four-fermion and gauge coupling criticality curves for dynamical chiral symmetry breaking. The results show that when the zero-momentum gauge coupling $α(0) < α_0(0)$, the critical gauge coupling in the pure gauge interaction case, the minimal critical four-fermion coupling $β_{\rm min}$ is always non-zero and positive and will go up as the $α(0)$ decreases. The use of the exact solutions also allow us to make quite definite estimations of the momentum scales where chiral symmetry breaking would happen if the values of an infrared parameter $ξ$ are given separately.

hep-ph↗

arXiv1998

Discrete symmetry breaking and restoration at finite temperature in 3D Gross-Neveu model

Dynamical spontaneous breaking of some discrete symmetries including special parities and time reversal and their restoration at finite temperature T are researched in 3D Gross-Neveu model by means of Schwinger-Dyson equation in the real-time thermal field theory in the fermion bubble diagram approximation. When the momentum cut-off $Λ$ is large enough, the equation of critical chemical potential $μ_c$ and critical temperature $T_c$ will be $Λ$-independent and identical to the one obtained by auxialiary scalar field approach. The dynamical fermion mass m, as the order parameter of symmetry breaking, has the same $(T_c-T)^{1/2}$ behavior as one in 4D NJL-model when T is less than and near $T_c$ and this shows the second-order phase transition feature of the symmetry restoration at $T>T_c$. It is also proven that no scalar bound state could exist in this model.

hep-th↗