Flavour constraints on scenarios with two or three heavy squark generations

TL;DR

This paper revisits flavour constraints on supersymmetric models with heavy squark generations, providing new NLO QCD limits for scenarios with three heavy families and comparing them to two-family cases.

Contribution

It introduces the first NLO QCD limits for scenarios with three heavy squark generations and offers practical tools for calculating Wilson coefficients in these models.

Findings

NLO QCD corrections significantly affect flavour constraints.

Three heavy squark generations impose different limits than two.

Provided ready-to-use calculations for Wilson coefficients at 2 GeV.

Abstract

We re-assess constraints from flavour-changing neutral currents in the kaon system on supersymmetric scenarios with a light gluino, two heavy generations of squarks and a lighter third generation. We compute for the first time limits in scenarios with three heavy squark families, taking into account QCD corrections at the next-to-leading order. We compare our limits with those in the case of two heavy families. We use the mass insertion approximation and consider contributions from gluino exchange to constrain the mixing between the first and second squark generation. While it is not possible to perform a general analysis, we assess the relevance of each kind of flavour- and CP-violating parameters. We also provide ready to use magic numbers for the computation of the Wilson coefficients at 2 GeV for these scenarios.