Correlation function with the insertion of zero modes of modular Hamiltonians

Zero modes of modular Hamiltonian of one interval are found in momentum space for two dimensional massless free scalar theory. Finite correlators are extracted from separate region connected correlation functions with the insertion of zero modes. Correlators of $(n,1)$-type are claimed to be conformal block up to a set of theory dependent constants. We fix the correlators of $(2,1)$-type with the coefficients of three point function in 2d CFTs.