High Precision Spectroscopy of Pionic and Muonic X-Rays to Extract an Upper Limit for the Muon--Neutrino Mass
Abstract
A new experiment for a high precision measurement of the pion mass is presented. It combines the cyclotron trap to produce pionic atoms in a small volume, with a doubly focussing crystal spectrometer to measure pionic and muonic X-ray transitions with high accuracy. The muonic X-rays will serve as new high precision standards. The first test experiments demonstrate the feasibility of the project. It yielded a preliminary value for the pion mass of (139570.71± 0.53) keV c2. In combination with a recent muon momentum result a new value for the muon neutrino was obtained: M2νμ=(0.02898±0.03267) MeV2/c4. With some improvements which are being prepared, the next measurement can be expected to yield an accuracy of better than 1ppm for the pion mass and hence a limit smaller than 70 keVc2 for the neutrino mass.
- Publication:
-
Acta Physica Polonica B
- Pub Date:
- January 1998
- Bibcode:
- 1998AcPPB..29..131B