LPCTRAP05 · Precision tests of the Standard Model using beta decay and a novel transparent Paul trap
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-04-16 → 2007-04-15
- EU contribution
- €150,237
- Participants
- 1
- Scheme
- EIF
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Results in brief
Final Activity Report Summary - LPCTRAP05 (Precision tests of the Standard Model using beta decay and a novel transparent Paul trap)
Several experiments on stable beams, namely 4He+, 12C2+, 35Cl+ and 36,40Ar+, delivered at different energies were carried out to improve the efficiency figure of the LPCTrap facility. Several modifications along the beam line were implemented among the runs (NIMA). Two experiments on 6He+ ions took place. The first experiment, during May 2005, provided the proof of principle for the correlation measurement. These were the first in-trap decays in ion traps. The second experiment was performed at the end of July 2006 and provided about 100 000 beta-neutrino coincidences from the decay of 6He+ ions. A preliminary analysis was carried out to identify the effects of the RF field and size of the ion cloud on the time-of-flight spectrum of recoil ions which was obtained in the second 6He+ experiment. The analysis already showed an effect of the phase of the RF field in the time-of-flight spectrum. An effect of the size of the ion cloud was not observed, since it was hidden by the RF field. More experiments would be needed to determine a final value of 'a'. Even though the statistics improved considerably from the first 6He+ run in May 2005 to the second 6He+ run in July 2006, a competitive value of 'a' needed further improvements. Several proceedings were published in peer-review articles. The fellow was the first author in the NIMA paper 'The LPCTrap facility: a novel transparent Paul for high-precision experiments' as well as in the proceedings for the TCP'06 contribution. These proceedings were published in 'Hyperfine Interactions' as recommended by the referee. Other publications written by other members of the group were also submitted.
Data: CORDIS, © European Union
Project objective
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.
Original text from CORDIS.
Participants
- CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE / INSTITUT NATIONAL DE PHYSIQUE NUCLÉAIRE ET DE PHYSIQUE DES PARTICULES · PARISCoordinatorCity levelFrance
Links
Data: CORDIS, © European Union