Processes involving narrow jets receive perturbative corrections enhanced by
logarithms of the jet opening angle and the ratio of the energies inside and
outside the jets. Analyzing cone-jet processes in effective field theory, we
find that in addition to soft and collinear fields their description requires
degrees of freedom which are simultaneously soft and collinear to the jets.
These collinear-soft particles can resolve individual collinear partons,
leading to a complicated multi-Wilson-line structure of the associated
operators at higher orders. Our effective field theory provides, for the first
time, a factorization formula for a cone-jet process, which fully separates the
physics at different energy scales. Its renormalization-group equations control
all logarithmically enhanced higher-order terms, in particular also the
non-global logarithms.Comment: 9 pages, 1 figure. v2: PRL versio
