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Wietfeldt F, Byron W, Collett B, Darius G, DeAngelis C, Dewey M, Hassan M, Jones G, Komives A, Mendenhall M, Nico J, Stephenson E. aCORN: Measuring the electron-antineutrino correlation in neutron beta decay. EPJ Web Conf 2019. [DOI: 10.1051/epjconf/201921904008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), the most precise to date. The second run on the new NG-C high flux beam line promises an improvement in precision to ¡ 2%. In addition we show that an improved measurement of the neutrino asymmetry (B-coefficient) can be made using the aCORN apparatus on a highly polarized neutron beam.
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Collett B, Bateman F, Bauder WK, Byrne J, Byron WA, Chen W, Darius G, DeAngelis C, Dewey MS, Gentile TR, Hassan MT, Jones GL, Komives A, Laptev A, Mendenhall MP, Nico JS, Noid G, Park H, Stephenson EJ, Stern I, Stockton KJS, Trull C, Wietfeldt FE, Yerozolimsky BG. aCORN: An experiment to measure the electron-antineutrino correlation coefficient in free neutron decay. Rev Sci Instrum 2017; 88:083503. [PMID: 28863637 PMCID: PMC6078102 DOI: 10.1063/1.4996542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects.
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Affiliation(s)
- B. Collett
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - F. Bateman
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - W. K. Bauder
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - J. Byrne
- University of Sussex, Brighton, Sussex, BA1 9QH, UK
| | - W. A. Byron
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - W. Chen
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
- University of Maryland, College Park, Maryland 20742, USA
| | - G. Darius
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - C. DeAngelis
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M. S. Dewey
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - T. R. Gentile
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - M. T. Hassan
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - G. L. Jones
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - A. Komives
- Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135, USA
| | - A. Laptev
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M. P. Mendenhall
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - J. S. Nico
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - G. Noid
- CEEM, Indiana University, Bloomington, IN 47408, USA
| | - H. Park
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | | | - I. Stern
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | | | - C. Trull
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - F. E. Wietfeldt
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
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Darius G, Byron WA, DeAngelis CR, Hassan MT, Wietfeldt FE, Collett B, Jones GL, Dewey MS, Mendenhall MP, Nico JS, Park H, Komives A, Stephenson EJ. Measurement of the Electron-Antineutrino Angular Correlation in Neutron β Decay. Phys Rev Lett 2017; 119:042502. [PMID: 29341742 DOI: 10.1103/physrevlett.119.042502] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Indexed: 06/07/2023]
Abstract
We report the first result for the electron-antineutrino angular correlation (a coefficient) in free neutron β decay from the aCORN experiment. aCORN uses a novel method in which the a coefficient is proportional to an asymmetry in proton time of flight for events where the β electron and recoil proton are detected in delayed coincidence. Data are presented from a 15 month run at the NIST Center for Neutron Research. We obtained a=-0.1090±0.0030(stat)±0.0028(sys), the most precise measurement of the neutron a coefficient reported to date.
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Affiliation(s)
- G Darius
- Tulane University, New Orleans, Louisiana 70118, USA
| | - W A Byron
- Tulane University, New Orleans, Louisiana 70118, USA
| | - C R DeAngelis
- Tulane University, New Orleans, Louisiana 70118, USA
| | - M T Hassan
- Tulane University, New Orleans, Louisiana 70118, USA
| | - F E Wietfeldt
- Tulane University, New Orleans, Louisiana 70118, USA
| | - B Collett
- Hamilton College, Clinton, New York 13323, USA
| | - G L Jones
- Hamilton College, Clinton, New York 13323, USA
| | - M S Dewey
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - M P Mendenhall
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J S Nico
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - H Park
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - A Komives
- DePauw University, Greencastle, Indiana 46135, USA
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Hassan MT, Bateman F, Collett B, Darius G, DeAngelis C, Dewey MS, Jones GL, Komives A, Laptev A, Mendenhall MP, Nico JS, Noid G, Stephenson EJ, Stern I, Trull C, Wietfeldt FE. The aCORN Backscatter-Suppressed Beta Spectrometer. Nucl Instrum Methods Phys Res A 2017; 867:10.1016/j.nima.2017.05.029. [PMID: 31092963 PMCID: PMC6512858 DOI: 10.1016/j.nima.2017.05.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Backscatter of electrons from a beta spectrometer, with incomplete energy deposition, can lead to undesirable effects in many types of experiments. We present and discuss the design and operation of a backscatter-suppressed beta spectrometer that was developed as part of a program to measure the electronantineutrino correlation coefficient in neutron beta decay (aCORN). An array of backscatter veto detectors surrounds a plastic scintillator beta energy detector. The spectrometer contains an axial magnetic field gradient, so electrons are efficiently admitted but have a low probability for escaping back through the entrance after backscattering. The design, construction, calibration, and performance of the spectrometer are discussed.
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Affiliation(s)
- M T Hassan
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - F Bateman
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - B Collett
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - G Darius
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - C DeAngelis
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M S Dewey
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - G L Jones
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - A Komives
- Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135, USA
| | - A Laptev
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M P Mendenhall
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J S Nico
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - G Noid
- CEEM, Indiana University, Bloomington, IN 47408, USA
| | | | - I Stern
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - C Trull
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - F E Wietfeldt
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
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