Obtaining gluon propagator with Leibbrandt–Mandelstam prescription

The quantization problems of the gluon fields are investigated in the lightcone gauge, nμAμa(x)=0, where n2=0. In this gauge, the gluon propagator has unphysical poles of kind 1/(nk). In order to remove these singularities, Leibbrandt and Mandelstam have proposed a new prescription. In this work we introduced a new modified lightcone gauge, which is nμ+iε(n∗k)k2kμAμa=0 where nμ∗ is the dual vector to nμ. We proved that Leibbrandt–Mandelstam prescription can be obtained on the basis of consistent quantization. The Ward identity in the modified lightcone gauge was also investigated.