Exploring the flavour structure of the high-scale MSSM

TL;DR

This paper investigates how quark flavour-changing observables can reveal the flavour structure of the high-scale MSSM, even with superpartner masses up to 100 TeV, highlighting key observables for future experiments.

Contribution

It introduces four frameworks based on approximate flavour symmetries to analyze the sensitivity of flavour observables in the high-scale MSSM regime.

Findings

Six low-energy observables can effectively characterize the flavour frameworks.

These observables remain relevant even with superpartner masses up to 100 TeV.

Future experiments could significantly improve the understanding of MSSM flavour structure.

Abstract

We analyse the sensitivity of quark flavour-changing observables to the MSSM, in a regime of heavy superpartner masses. We analyse four distinct and motivated frameworks characterising the structure of the soft-breaking terms by means of approximate flavour symmetries. We show that a set of six low-energy observables with realistic chances of improvement in the near future, namely $\Delta M_{s,d}$, $\epsilon_K$, $\epsilon_K'/\epsilon_K$, $\mathcal{B} (K\to \pi\nu\bar\nu)$, and the phase of $D$--$\bar D$ mixing, could play a very important role in charactering these frameworks in a regime of superpartner masses up to $\mathcal{O}(100)$~TeV. We show that these observables remain very interesting even in a long-term perspective, i.e.~even taking into account the direct mass reach of the most ambitious future high-energy colliders.