The MuCap experiment measures the singlet rate Lambda_S of muon capture on the proton. A negative muon beam is stopped in a time projection chamber filled with ultra-pure hydrogen gas at 10 bar and room temperature. In combination with the surrounding decay electron detectors, the lifetime of muons in hydrogen can be measured to determine LS to a final precision of 1%. The capture rate is then used to derive the nucleon's pseudoscalar form factor gP. Our first-stage result, gP= 7.3\pm1., will soon be updated with the final analysis of the full statistics reducing the error by a factor of ~2.
@article{arxiv.1110.5090,
title = {Muon Capture on the Proton},
author = {P. Winter},
journal= {arXiv preprint arXiv:1110.5090},
year = {2015}
}
Comments
Talk given at the 19th Particles & Nuclei International Conference (PANIC 2011), 07/24-29 2011, Massachusetts Institute of Technology, Cambridge, MA, USA