Abstract
A measurement of the neutrino asymmetry is presented which represents the first search for new physics using polarized radioactive atoms initially cooled and confined in a magneto-optical trap. Optical pumping and photoionization techniques are used to generate and measure, in situ, a highly spin-polarized (96.5 (0.8) %) sample of the short-lived β+-emitter 37K. The angular distribution of neutrinos from this polarized decay, inferred from the daughter recoil asymmetry, is used to search for a hypothetical V + A current in the weak interaction. We find the ν asymmetry parameter to be Bν = - 0.755 ± 0.020 (stat) ± 0.013 (syst), in agreement with the standard model's purely V - A interaction.
Original language | English |
---|---|
Pages (from-to) | 370-375 |
Number of pages | 6 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 649 |
Issue number | 5-6 |
DOIs | |
State | Published - 14 Jun 2007 |
Keywords
- Atom trapping
- Neutrino asymmetry
- Nuclear β decay
- Optical pumping
- Parity violation
- Right-handed currents