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Precision Measurement Of The Neutron's Beta Asymmetry Using Ultra-Cold Neutrons

Makela, M. and Back, H. O. and Melconian, D. and Plaster, B. (2006) Precision Measurement Of The Neutron's Beta Asymmetry Using Ultra-Cold Neutrons. In: Particles and Nuclei. AIP Conference Proceedings. No.842. American Institute of Physics , Melville, NY, pp. 808-810. ISBN 0-7354-0338-4.

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A measurement of A_β, the correlation between the electron momentum and neutron (n) spin (the beta asymmetry) in n beta-decay, together with the n lifetime, provides a method for extracting fundamental parameters for the charged-current weak interaction of the nucleon. In particular when combined with decay measurements, one can extract the V_(ud) element of the CKM matrix, a critical element in CKM unitarity tests. By using a new SD_2 super-thermal source at LANSCE, large fluxes of UCN (ultra-cold neutrons) are expected for the UCNA project. These UCN will be 100% polarized using a 7 T magnetic field, and directed into the β spectrometer. This approach, together with an expected large reduction in backgrounds, will result in an order of magnitude reduction in the critical systematic corrections associated with current n β-asymmetry measurements. This paper will give an overview of the UCNA Aβ measurement as well as an update on the status of the experiment.

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Additional Information:© 2006 American Institute of Physics. Issue Date: 11 July 2006.
Subject Keywords:beta-decay, ultracold neutrons, elementary particle electric moment, baryon spin, charged currents
Series Name:AIP Conference Proceedings
Issue or Number:842
Classification Code:PACS: 23.40.Bw; 14.20.Dh; 12.15.Hh
Record Number:CaltechAUTHORS:20110722-072853069
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Official Citation:Precision Measurement Of The Neutron's Beta Asymmetry Using Ultra-Cold Neutrons M. Makela, H. O. Back, D. Melconian, and B. Plaster, AIP Conf. Proc. 842, 808 (2006), DOI:10.1063/1.2220389
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:24501
Deposited By: Ruth Sustaita
Deposited On:22 Jul 2011 15:30
Last Modified:03 Oct 2019 02:57

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