A peculiar property of SUSY amplitudes at high energy

TL;DR

This paper reveals a unique SUSY property causing the absence of single logarithms in high-energy electroweak corrections, leading to simplified relations among various processes as tests of SUSY models.

Contribution

It uncovers a general SUSY cancellation in high-energy electroweak corrections, simplifying the analysis of related processes and providing new tests for SUSY models.

Findings

Only quadratic logarithms appear in MSSM high-energy corrections.

The cancellation is a fundamental SUSY property of specific vertices.

Simplified relations among processes serve as SUSY tests.

Abstract

We observe that the electroweak one loop correction to the quark+gluon to quark+Higgs amplitude at high energy involves both single and quadratic logarithms of the energy in the SM case but only quadratic logarithms in the MSSM case. We explore the origin of this special SUSY cancellation, both in a diagrammatic way and through the splitting+Parameter Renormalization procedure. We show that it is not an accident but a remarkableand general SUSY property of the renormalized Higgs-fermion-fermion and Higgsino-sfermion-fermion vertices which directly reflects in such processes, for example in $bg\to tH^-$, $bg\to bH^0$, $bg\to bh^0$, $bg\to bA^0$, and through equivalence in $bg\to tW^-_{long}$, $bg\to bZ_{long}$, as well as in $bg\to \tilde{t}\chi^-$, $bg\to\tilde{b}\chi^0$. This simplification of the high energy behaviour (which only leaves quadratic logarithms involving pure gauge couplings without any free parameter) allows to write simple relations among these various processes which constitute genuine tests of the assumed SUSY model.