Sudakov effects in electroweak corrections

In perturbation theory the infrared structure of the electroweak interactio ns 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 energ y growing corrections can be particularly relevant fur the planned Next Lin ear 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 com ing from SUSY loops. (C) 1999 Published by Elsevier Science B.V. All rights reserved.