Non-decoupling two-loop corrections to (g-2)_\mu\ from fermion/sfermion loops in the MSSM

TL;DR

This paper calculates significant two-loop fermion/sfermion contributions to the muon (g-2) in the MSSM, highlighting their non-decoupling nature and impact on the total prediction, especially at large sfermion masses.

Contribution

It provides the first detailed analysis of fermion/sfermion two-loop effects in the MSSM, showing they can dominate previous contributions and are non-decoupling at high masses.

Findings

Up to 15% correction for 20 TeV sfermions.

Up to 30% correction for 1000 TeV sfermions.

Contributions include universal quantities eltalpha and eltaensity.

Abstract

Two-loop contributions to the muon (g-2) from fermion/sfermion loops in the MSSM are presented, and an overview of the full MSSM prediction for (g-2) is given with emphasis on the behaviour in scenarios which are compatible with LHC data, including scenarios with large mass splittings. Compared to all previously known two-loop contributions, the fermion/sfermion-loop contributions can yield the largest numerical results. The new contributions contain the important universal quantities \Delta\alpha\ and \Delta\rho, and for large sfermion masses the contributions are non-decoupling and logarithmically enhanced. We find up to 15% (30%) corrections for sfermion masses in the 20 TeV (1000 TeV) range.