Zero Mode and Symmetry Breaking on the Light Front

Abstract

Much attention has recently been paid to the light-front (LF) quantization [1] as a promising approach to solve the nonperturbative dynamics. The most important aspect of the LF quantization is that the physical LF vacuum is simple, or even trivial [2], However, such a trivial vacuum, which is vital to the whole LF approach, can be realized only if we can remove the so-called zero mode out of the physical Fock space (“zero mode problem” [3]).