## Threshold Resummation in Momentum Space from Effective Field Theory

Methods from soft-collinear effective theory are used to perform the threshold resummation of Sudakov logarithms for the deep-inelastic structure function F{sub 2}(x,Q{sup 2}) in the end-point region x{yields}1 directly in momentum space. An explicit all-order formula is derived, which expresses the short-distance coefficient function C in the convolution F{sub 2}=C(multiply-in-circle sign){phi}{sub q} in terms of Wilson coefficients and anomalous dimensions defined in the effective theory. Contributions associated with the physical scales Q{sup 2} and Q{sup 2}(1-x) are separated from nonperturbative hadronic physics in a transparent way. A crucial ingredient to the momentum-space resummation is the exact solution to the integro-differentialmore »