Top quark threshold production in γγ collision in the next-to-leading order Original Research Article

The total cross section of the top quark-antiquark pair production near threshold in γγ collision is computed analytically up to the next-to-leading order in perturbative and non-relativistic expansion for a general photon helicity. The approximation includes the first-order corrections in the strong coupling constant and the heavy quark velocity to the non-relativistic Coulomb approximation.