Uniaxial Lifshitz Point at $O(\epsilon_L^2)$

The critical exponents $\nu_{L2}, \eta_{L2}$ and $\gamma_{L2}$ of a uniaxial Lifshitz point are calculated at two-loop level using renormalization group and $\epsilon_{L}$-expansion techniques. We found a new constraint involving the loop momenta along the competition axis, which allows to solve the two-loop integrals. The exponent $\gamma_{L2}$ obtained using our method is in good agreement with numerical estimates based on Monte Carlo simulations.