Measuring MSSM CP-violating Phases through Spin Correlated Supersymmetric Tri-lepton Signatures at the Tevatron

TL;DR

This paper analyzes how CP-violating phases in the MSSM affect tri-lepton signals at the Tevatron, exploring the potential to measure these phases through spin correlations and T-odd observables.

Contribution

It provides a detailed study of CP-violating effects on supersymmetric tri-lepton signals, including the impact of experimental constraints and the use of T-odd observables for phase measurement.

Findings

CP-violating phases influence production cross sections and decay branching ratios.

Spin correlations lead to measurable CP-even observables like invariant mass and angular distributions.

T-odd momentum triple products can potentially measure CP-violating phases directly.

Abstract

We provide a detailed analysis of the supersymmetric tri-lepton signals for sparticle searches at the Tevatron in the minimal supersymmetric standard model with general CP-violating phases but without flavor mixing among sfermions of different generation. The stringent experimental constraints on the CP-violating phases from the electron and neutron electric dipole moments are included in the analysis for two exemplary scenarios of the SUSY parameters; one with decoupled first two generation sfermions and the other with non-decoupled sfermions. In both scenarios, the production cross section and the branching fractions of the leptonic chargino and neutralino decays are sensitive to CP-violating phases. The production-decay spin correlations lead to several non-trivial CP-even observables such as the lepton invariant mass distribution and the lepton angular distribution, and several interesting T-odd (CP-odd) momentum triple products. The possibility of measuring the CP-violating phases directly through those T-odd observables is investigated in detail.