Proposed Measurement of the Beta-Neutrino Correlation in Neutron Decay

B Collett; R Anderman; S Balashov; F B Bateman; J Byrne; M S Dewey; B M Fisher; L Goldin; G Jones; A Komives; T Konopka; M Leuschner; Yu Mostovoy; J S Nico; A K Thompson; C Trull; F E Wietfeldt; R Wilson; B G Yerozolimsky

doi:10.6028/jres.110.060

Proposed Measurement of the Beta-Neutrino Correlation in Neutron Decay

J Res Natl Inst Stand Technol. 2005 Aug 1;110(4):401-5. doi: 10.6028/jres.110.060. Print 2005 Jul-Aug.

Authors

B Collett¹, R Anderman¹, S Balashov², F B Bateman³, J Byrne⁴, M S Dewey³, B M Fisher⁵, L Goldin⁶, G Jones¹, A Komives⁷, T Konopka¹, M Leuschner⁸, Yu Mostovoy², J S Nico³, A K Thompson³, C Trull⁵, F E Wietfeldt⁵, R Wilson⁶, B G Yerozolimsky⁶

Affiliations

¹ Physics Department, Hamilton College, Clinton, NY 13323.
² Kurchatov Institute, Moscow, Russia.
³ National Institute of Standards and Technology, Gaithersburg, MD 20899.
⁴ University of Sussex, United Kingdom.
⁵ Department of Physics, Tulane University, New Orleans, LA 70118.
⁶ Physics Department, Harvard University, Cambridge, MA 02139.
⁷ Physics Department, DePauw University, Greencastle, IN 46135.
⁸ Indiana University Cyclotron Facility, Bloomington, IN 47408.

Abstract

Currently, the beta-neutrino asymmetry has the largest uncertainty (4 %) of the neutron decay angular correlations. Without requiring polarimetry this decay parameter can be used to measure λ (ga/gv ), test Cabibbo-Kobayashi-Maskawa (CKM) unitarity limit scalar and tensor currents, and search for Charged Vector Current (CVC) violation. We propose to measure the beta-neutrino asymmetry coeffcient, a, using time-of-flight for the recoil protons. We hope to achieve a systematic uncertainty of σa / a ≈ 1.0 %. After tests at Indiana University's Low Energy Neutron Source (LENS), the apparatus will be moved to the National Institute of Standards and Technology (NIST) where the measurement can achieve a statistical uncertainty of 1 % to 2 % in about 200 beam days.

Keywords: CKM unitarit; beta decay; beta-neutrino correlation; neutron decay.