C T for non-unitary CFTs in higher dimensions

The coefficient C T of the conformal energy-momentum tensor two-point function is determined for the non-unitary scalar CFTs with four- and six-derivative kinetic terms. The results match those expected from large-N calculations for the CFTs arising from the O(N) non-linear sigma and Gross-Neveu models in specific even dimensions. C T is also calculated for the CFT arising from (n − 1)-form gauge fields with derivatives in 2n + 2 dimensions. Results for (n − 1)-form theory extended to general dimensions as a non-gauge-invariant CFT are also obtained; the resulting C T differs from that for the gauge-invariant theory. The construction of conformal primaries by subtracting descendants of lower-dimension primaries is also discussed. For free theories this also leads to an alternative construction of the energy-momentum tensor, which can be quite involved for higher-derivative theories.