# Physics of fundamental Symmetries and Interactions - PSI2016

Oct 16 – 20, 2016
Europe/Zurich timezone

## The MuSun Experiment: First analysis of production data

Oct 19, 2016, 3:00 PM
20m
Oral Fundamental physics and precision experiments with muons, pions, neutrons, antiprotons, and other particles

### Speaker

Ms Rachel Ryan (University of Washington)

### Description

Using a unique cryogenic time projection chamber as an active stopping target, the MuSun experiment has acquired the $10^{10}$ fully reconstructed muon decay events necessary to measure the rate of muon capture on the deuteron to better than 1.5\% precision. Once completed, the analysis will lead to a benchmark result in calibrating weak interactions in the two nucleon system, relevant for calculating fundamental nuclear reactions within modern effective field theories. MuSun employs a technique to extract the capture rate via measurement of the deviation of the negative muon lifetime in deuterium gas from the positive muon lifetime. Such a technique requires excellent gas purity, knowledge of the $\mu$d hyperfine state prior to capture, and verification that each muon stopped within the gas target. Advanced muon tracking algorithms have been developed to reduce systematic effects associated with muon catalyzed fusion interference, in addition to methods to estimate gas purity. These analysis tools are now being applied to the first high statistics production dataset from the 2014 run, consisting of $5\times10^{9}$ events. An overview of systematics will be presented, along with the status of the first analysis of production data.

### Primary author

Ms Rachel Ryan (University of Washington)

### Co-author

The MuSun Collaboration The MuSun Collaboration (University of Washington, PNPI, Boston University, University of Kentucky, Regis University)

 Slides