Operator expansion for the elastic limit

A leading twist expansion in terms of bilocal operators is proposed for the structure functions of deeply inelastic scattering near the elastic limit x --> 1, which is also applicable to a range of other processes. Operators of increasing dimensions contribute to logarithmically enhanced terms which are suppressed by corresponding powers of 1 - x. For the longitudinal structure function, in moment (N) space, all the logarithmic contributions of order ln(k)N/N are shown to be resummable in terms of the anomalous dimension of the leading operator in the expansion. [S0031-9007(98)07452-3].