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Measurement of the neutron β-asymmetry parameter A_0 with ultracold neutrons

Plaster, B. and Carr, R. and Filippone, B. W. and Hickerson, K. P. and Ito, T. M. and Liu, J. and Martin, J. W. and Mendenhall, M. P. and Pérez Galván, A. and Russell, R. and Schmid, R. and Tipton, B. and Yuan, J. (2012) Measurement of the neutron β-asymmetry parameter A_0 with ultracold neutrons. Physical Review C, 86 (5). Art. No. 055501. ISSN 0556-2813.

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We present a detailed report of a measurement of the neutron β-asymmetry parameter A_0, the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T 2×2π solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages located on both ends of the spectrometer. From an analysis of data acquired during runs in 2008 and 2009, we report A_0=−0.11966±0.00089_(−0.00140)^(+0.00123), from which we extract a value for the ratio of the weak axial-vector and vector coupling constants of the nucleon, λ=g_A/g_V=−1.27590±0.00239_(−0.00377)^(+0.00331). Complete details of the analysis are presented.

Item Type:Article
Related URLs:
URLURL TypeDescription
Filippone, B. W.0000-0002-2618-2688
Hickerson, K. P.0000-0001-7647-119X
Ito, T. M.0000-0003-3494-6796
Additional Information:© 2012 American Physical Society. Received 25 July 2012; published 12 November 2012. This work was supported in part by the Department of Energy Office of Nuclear Physics (Grant No. DE-FG02-08ER41557), the National Science Foundation (Grants No. NSF-0555674, No. NSF-0855538, No. NSF-0653222, and No. NSF-1005233), and the Los Alamos National Laboratory LDRD program. We gratefully acknowledge the support of the LANSCE and AOT divisions of Los Alamos National Laboratory.
Funding AgencyGrant Number
Department of Energy (DOE) Office of Nuclear PhysicsDE-FG02-08ER41557
Los Alamos National Laboratory LDRD ProgramUNSPECIFIED
Los Alamos National Laboratory LANSCE DivisionUNSPECIFIED
Los Alamos National Laboratory AOT DivisionsUNSPECIFIED
Issue or Number:5
Classification Code:PACS: 23.40.Bw, 12.15.Ff, 13.30.Ce, 14.20.Dh
Record Number:CaltechAUTHORS:20130122-082734260
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Official Citation:Measurement of the neutron β-asymmetry parameter A0 with ultracold neutrons B. Plaster et al. (UCNA Collaboration) Published 12 November 2012 (49 pages) 055501
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36489
Deposited By: Ruth Sustaita
Deposited On:22 Jan 2013 17:02
Last Modified:09 Mar 2020 13:18

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