# Spin dynamics investigations for the EDM experiment at COSY

## TL;DR

This paper develops a matrix formalism for precise numerical predictions of spin dynamics in storage rings like COSY, aiding the search for electric dipole moments by improving spin-tracking algorithms.

## Contribution

It introduces a matrix formalism focused on spin rotations on the closed orbit, guiding the development of accurate spin-tracking codes for EDM experiments at COSY.

## Key findings

- Provides a formalism for spin rotations on the closed orbit
- Guides development of spin-tracking algorithms with realistic elements
- Supports precision measurements in EDM searches

## Abstract

Precision experiments, such as the search for a deuteron electric dipole moments using a storage rings like COSY, demand for an understanding of the spin dynamics with unprecedented accuracy. In such an enterprise, numerical predictions play a crucial role for the development and later application of spin-tracking algorithms. Various measurement concepts involving polarization effects induced by an RF Wien filter and static solenoids in COSY are discussed. The matrix formalism, applied here, deals \textit{solely} with spin rotations \textit{on the closed orbit} of the machine, and is intended to provide \textit{numerical} guidance for the development of beam and spin-tracking codes for rings that employ realistic descriptions of the electric and magnetic bending and focusing elements, solenoids etc., and a realistically-modeled RF Wien filter.