2009/10/30 by B. I. Ermolaev, Ermolaev, B. I.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.0910.5877
4 pages, 4 figures
arxiv created 2009/10/30 · arxiv updated 2009/12/01
We present a short comment on resummation of double-logarithmic (DL) contributions to decays of W and Z -bosons into charged fermion pairs. We show that resummation of DL corrections to the Z -boson decay leads to standard Sudakov form factor with the negative exponent independently of the boson is on-shell or off-shell. In contrast, the Sudakov exponent for the W - decay is negative (positive) when the W-boson is on-shell (off-shell). In this connection we consider applicability of the Dispersion Relations to the case when the imaginary parts contain infrared-divergent contributions.