Improving the Hadron Physics of Non-Standard-Model Decays: Example Bounds on R-parity Violation

TL;DR

This paper demonstrates how to precisely control final-state interactions in R-parity-violating supersymmetric decays, leading to significantly improved bounds on the relevant couplings from tau decay data.

Contribution

It introduces a method to accurately account for strong final-state interactions, enabling more precise extraction of parameters in non-standard-model decay processes.

Findings

Bounds on R-parity-violating couplings are an order of magnitude stronger than previous limits.

Controlled final-state interactions improve the accuracy of parameter extraction.

Focus on tau --> mu pi+ pi- decays as a case study.

Abstract

Using the example of selected decays driven by R-parity-violating supersymmetric operators, we demonstrate how strong final-state interactions can be controlled quantitatively with high precision, thus allowing for a more accurate extraction of effective parameters from data. In our examples we focus on the lepton-flavor-violating decays tau --> mu pi+ pi-. In R-parity violation these can arise due to the product of two couplings. We find bounds that are an order of magnitude stronger than previous ones.