Structure of the action
The action consists of the matter term (a generic sigma-model) and some ghost terms.
The ghost terms are of the form:
with the following notations:
and are scalars on the worldsheet taking values in the spin bundle over the target space; they satisfy the pure spinor constraints
and are 1-forms on the worldsheet taking values in the dual to the spin bundle over the target space; there is some gauge symmetry because and satisfy the pure spinor constraints
is the pairing between the conjugate to the spin bundle and the spin bundle
the Dolbeault operators and are explained here
Strictly speaking, instead of and one has to use the target space-covariant
derivatives:
where is some connection in the target space spin bundle.
There is also some quartic term .