Naturalness from stop decays

TL;DR

This paper discusses how observing specific stop or sbottom decays involving charged Higgs bosons at the LHC can provide direct evidence of supersymmetry by measuring a unique scalar quartic interaction related to Yukawa couplings.

Contribution

It identifies a measurable scalar quartic decay channel at the LHC that can serve as a direct test of supersymmetry, especially in compressed spectra scenarios.

Findings

The decay of stop/sbottom to charged Higgs is a potential discovery channel.

Measuring this decay confirms the scalar quartic's relation to Yukawa couplings.

This decay mode can be dominant in certain supersymmetric spectra.

Abstract

In supersymmetric theories, there is a scalar quartic related to the top and bottom yukawas that gives LHC observable decays of the stop or sbottom. After electroweak symmetry breaking, this quartic induces the decay of the stop (sbottom) to a charged Higgs and the sbottom (stop) without allowing for the corresponding channel involving the W boson. Unlike other scalar quartics, this scalar quartic is measurable at the LHC and for compressed spectra may even be the discovery channel for the stop or sbottom. Observing this decay and measuring the value of the quartic interaction would give direct evidence that the underlying theory is supersymmetric as only a fermionic symmetry can relate a scalar quartic to a yukawa interaction. This decay pathway is explored and situations where it can be the dominant decay mode for either the stop or the sbottom are highlighted. Measurement of this decay mode at the LHC would unambiguously show that the underlying theory of nature was supersymmetric.