Sudakov effects in electroweak corrections

In perturbation theory the infrared structure of the electroweak interactions produces large corrections proportional to double logarithms log(2)(s/m(2)), similar to Sudakov logarithms in QED, when the scale s is much larger than the typical mass rn of the particles running in the loops. These energy growing corrections can be particularly relevant fur the planned Next Linear Colliders. We study these effects in the Standard Model for the process e(+)e(-)-->f (f) over bar and we compare them with similar corrections coming from SUSY loops. (C) 1999 Published by Elsevier Science B.V. All rights reserved.