This proposal is centred on low energy tests of the Standard Model using ion traps. We plan to investigate accurately the beta-neutrino angular correlation coefficient 'a' in nuclear beta decay. According to the Standard Model, 'a' has a well defined value and any deviation from this value will open scenarios for new physics. This deviation can be only observed if 'a' is determined at the per mil level and therefore one needs of very precise measurements. Up to date, the most precise beta-neutrino angular c orrelation measurement was performed more than 40 years ago. The quoted uncertainty (Delta'a' =0.0030) is still high and a more precise measurement is requested. Our experiment endeavours to improve the precision in the determination of 'a' by a factor of 2 at least. The beta decaying source will be delivered by the low energy beam line of SPIRAL at GANIL, and after preparation and cooling, the nuclei will be stored inside the LPC transparent Paul trap. Beam preparation and cooling were already accomplished along the commissioning stage. With the decaying source almost at rest in the trap, we plan to detect the recoiling ions in coincidence with the beta particles. The coefficient 'a' will be derived from the fit to the experimental recoil-ion energy spectru m. A throughout study of the different contributions to the final uncertainty is essential in order to achieve our aim in precision. This accuracy study will be carried out by the candidate who will also contribute to set up and start the experiment at GAN IL. Our request of 24 months coincides exactly with the correlation measurement experiment.
Field of science
- /natural sciences/physical sciences/theoretical physics/particle physics
Call for proposal
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