Models

Many studies have investigated the vast aspects of the Schwinger effect by using gauge/gravity duality; however, the Schwinger effect in QCD-like gauge theories, especially where both electric and magnetic fields are simultaneously present, still need to be scrutinized. We use the deformed AdS₅ background metric for the gravity side of AdS/QCD correspondence since the potential of heavy quarks produced by this background metric agrees with experimental data. We use both potential analysis and calculation of the pair-production rate Γ to study the response of the QCD-like gauge theory to an external electromagnetic field and show that the two approaches agree. We identify critical electric fields E_S and E_C as lower and upper bounds of a range in which pair production can occur only by tunneling through a potential barrier. Below E_S, the potential barrier is insurmountable, and pair production cannot happen. Above E_C, there is no potential barrier to restrict the pair production. In addition, we find that a magnetic field perpendicular to the electric field suppresses Γ and increases E_S. In contrast, a pure parallel magnetic field does not affect the system's response to an external electric field, but it enhances Γ when a perpendicular magnetic field is also present.