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1
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Broussard LJ, Barrow JL, DeBeer-Schmitt L, Dennis T, Fitzsimmons MR, Frost MJ, Gilbert CE, Gonzalez FM, Heilbronn L, Iverson EB, Johnston A, Kamyshkov Y, Kline M, Lewiz P, Matteson C, Ternullo J, Varriano L, Vavra S. Experimental Search for Neutron to Mirror Neutron Oscillations as an Explanation of the Neutron Lifetime Anomaly. Phys Rev Lett 2022; 128:212503. [PMID: 35687456 DOI: 10.1103/physrevlett.128.212503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/25/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
An unexplained >4σ discrepancy persists between "beam" and "bottle" measurements of the neutron lifetime. A new model proposed that conversions of neutrons n into mirror neutrons n^{'}, part of a dark mirror sector, can increase the apparent neutron lifetime by 1% via a small mass splitting Δm between n and n^{'} inside the 4.6 T magnetic field of the National Institute of Standards and Technology Beam Lifetime experiment. A search for neutron conversions in a 6.6 T magnetic field was performed at the Spallation Neutron Source which excludes this explanation for the neutron lifetime discrepancy.
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Affiliation(s)
- L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J L Barrow
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | | | - T Dennis
- Department of Physics and Astronomy, East Tennessee State University, Johnson City, Tennessee 37614, USA
| | - M R Fitzsimmons
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M J Frost
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C E Gilbert
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - F M Gonzalez
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Heilbronn
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - E B Iverson
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Johnston
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Y Kamyshkov
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M Kline
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - P Lewiz
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - C Matteson
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - J Ternullo
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - L Varriano
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - S Vavra
- Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
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2
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Gonzalez FM, Fries EM, Cude-Woods C, Bailey T, Blatnik M, Broussard LJ, Callahan NB, Choi JH, Clayton SM, Currie SA, Dawid M, Dees EB, Filippone BW, Fox W, Geltenbort P, George E, Hayen L, Hickerson KP, Hoffbauer MA, Hoffman K, Holley AT, Ito TM, Komives A, Liu CY, Makela M, Morris CL, Musedinovic R, O'Shaughnessy C, Pattie RW, Ramsey J, Salvat DJ, Saunders A, Sharapov EI, Slutsky S, Su V, Sun X, Swank C, Tang Z, Uhrich W, Vanderwerp J, Walstrom P, Wang Z, Wei W, Young AR. Improved Neutron Lifetime Measurement with UCNτ. Phys Rev Lett 2021; 127:162501. [PMID: 34723594 DOI: 10.1103/physrevlett.127.162501] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
We report an improved measurement of the free neutron lifetime τ_{n} using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_{n} from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_{n} measurements and by performing a global likelihood fit to all data while self-consistently incorporating the β-decay lifetime. Both techniques achieve consistent results and find a value τ_{n}=877.75±0.28_{stat}+0.22/-0.16_{syst} s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.
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Affiliation(s)
- F M Gonzalez
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47405, USA
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E M Fries
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - C Cude-Woods
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - T Bailey
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - M Blatnik
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N B Callahan
- Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - J H Choi
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - S M Clayton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S A Currie
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Dawid
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47405, USA
| | - E B Dees
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - B W Filippone
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - W Fox
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47405, USA
| | - P Geltenbort
- Institut Laue-Langevin, CS 20156, 38042 Grenoble Cedex 9, France
| | - E George
- Tennessee Technological University, Cookeville, Tennessee 38505, USA
| | - L Hayen
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - K P Hickerson
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - M A Hoffbauer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K Hoffman
- Tennessee Technological University, Cookeville, Tennessee 38505, USA
| | - A T Holley
- Tennessee Technological University, Cookeville, Tennessee 38505, USA
| | - T M Ito
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Komives
- DePauw University, Greencastle, Indiana 46135, USA
| | - C-Y Liu
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47405, USA
| | - M Makela
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C L Morris
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R Musedinovic
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
| | - C O'Shaughnessy
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R W Pattie
- East Tennessee State University, Johnson City, Tennessee 37614, USA
| | - J Ramsey
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D J Salvat
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47405, USA
| | - A Saunders
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E I Sharapov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Slutsky
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - V Su
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - X Sun
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - C Swank
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - Z Tang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - W Uhrich
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Vanderwerp
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47405, USA
| | - P Walstrom
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - W Wei
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - A R Young
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA
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3
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Tang Z, Blatnik M, Broussard LJ, Choi JH, Clayton SM, Cude-Woods C, Currie S, Fellers DE, Fries EM, Geltenbort P, Gonzalez F, Hickerson KP, Ito TM, Liu CY, MacDonald SWT, Makela M, Morris CL, O'Shaughnessy CM, Pattie RW, Plaster B, Salvat DJ, Saunders A, Wang Z, Young AR, Zeck BA. Search for the Neutron Decay n→X+γ, Where X is a Dark Matter Particle. Phys Rev Lett 2018; 121:022505. [PMID: 30085691 DOI: 10.1103/physrevlett.121.022505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Fornal and Grinstein recently proposed that the discrepancy between two different methods of neutron lifetime measurements, the beam and bottle methods, can be explained by a previously unobserved dark matter decay mode, n→X+γ. We perform a search for this decay mode over the allowed range of energies of the monoenergetic γ ray for X to be dark matter. A Compton-suppressed high-purity germanium detector is used to identify γ rays from neutron decay in a nickel-phosphorous-coated stainless-steel bottle. A combination of Monte Carlo and radioactive source calibrations is used to determine the absolute efficiency for detecting γ rays arising from the dark matter decay mode. We exclude the possibility of a sufficiently strong branch to explain the lifetime discrepancy with 97% confidence.
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Affiliation(s)
- Z Tang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Blatnik
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J H Choi
- North Carolina State University, Raleigh, North Carolina 27695, USA
| | - S M Clayton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C Cude-Woods
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- North Carolina State University, Raleigh, North Carolina 27695, USA
| | - S Currie
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D E Fellers
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E M Fries
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | | | - F Gonzalez
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - K P Hickerson
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125, USA
| | - T M Ito
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C-Y Liu
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - S W T MacDonald
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Makela
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C L Morris
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | | | - R W Pattie
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B Plaster
- University of Kentucky, Lexington, Kentucky 40506, USA
| | - D J Salvat
- University of Washington, Seattle, Washington 98195-1560, USA
| | - A Saunders
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A R Young
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- North Carolina State University, Raleigh, North Carolina 27695, USA
| | - B A Zeck
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- North Carolina State University, Raleigh, North Carolina 27695, USA
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4
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Pattie RW, Callahan NB, Cude-Woods C, Adamek ER, Broussard LJ, Clayton SM, Currie SA, Dees EB, Ding X, Engel EM, Fellers DE, Fox W, Geltenbort P, Hickerson KP, Hoffbauer MA, Holley AT, Komives A, Liu CY, MacDonald SWT, Makela M, Morris CL, Ortiz JD, Ramsey J, Salvat DJ, Saunders A, Seestrom SJ, Sharapov EI, Sjue SK, Tang Z, Vanderwerp J, Vogelaar B, Walstrom PL, Wang Z, Wei W, Weaver HL, Wexler JW, Womack TL, Young AR, Zeck BA. Measurement of the neutron lifetime using a magneto-gravitational trap and in situ detection. Science 2018. [PMID: 29731449 DOI: 10.1126/science.aan8895,] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The precise value of the mean neutron lifetime, τn, plays an important role in nuclear and particle physics and cosmology. It is used to predict the ratio of protons to helium atoms in the primordial universe and to search for physics beyond the Standard Model of particle physics. We eliminated loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls. As a result of this approach and the use of an in situ neutron detector, the lifetime reported here [877.7 ± 0.7 (stat) +0.4/-0.2 (sys) seconds] does not require corrections larger than the quoted uncertainties.
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Affiliation(s)
- R W Pattie
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - N B Callahan
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | - C Cude-Woods
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.,Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - E R Adamek
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | - L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - S M Clayton
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - S A Currie
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E B Dees
- Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - X Ding
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - E M Engel
- West Point Military Academy, West Point, NY 10996, USA
| | - D E Fellers
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - W Fox
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | | | - K P Hickerson
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
| | - M A Hoffbauer
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - A T Holley
- Department of Physics, Tennessee Technological University, Cookeville, TN 38505, USA
| | - A Komives
- Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135-0037, USA
| | - C-Y Liu
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | | | - M Makela
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - C L Morris
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J D Ortiz
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J Ramsey
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - D J Salvat
- Department of Physics, University of Washington, Seattle, WA 98195-1560, USA
| | - A Saunders
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - S J Seestrom
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E I Sharapov
- Joint Institute for Nuclear Research, Dubna, Moscow region 141980, Russia
| | - S K Sjue
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Z Tang
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J Vanderwerp
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | - B Vogelaar
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - P L Walstrom
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - W Wei
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - H L Weaver
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J W Wexler
- Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - T L Womack
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - A R Young
- Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - B A Zeck
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.,Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
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5
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Pattie RW, Callahan NB, Cude-Woods C, Adamek ER, Broussard LJ, Clayton SM, Currie SA, Dees EB, Ding X, Engel EM, Fellers DE, Fox W, Geltenbort P, Hickerson KP, Hoffbauer MA, Holley AT, Komives A, Liu CY, MacDonald SWT, Makela M, Morris CL, Ortiz JD, Ramsey J, Salvat DJ, Saunders A, Seestrom SJ, Sharapov EI, Sjue SK, Tang Z, Vanderwerp J, Vogelaar B, Walstrom PL, Wang Z, Wei W, Weaver HL, Wexler JW, Womack TL, Young AR, Zeck BA. Measurement of the neutron lifetime using a magneto-gravitational trap and in situ detection. Science 2018; 360:627-632. [PMID: 29731449 DOI: 10.1126/science.aan8895] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 03/13/2018] [Indexed: 11/02/2022]
Abstract
The precise value of the mean neutron lifetime, τn, plays an important role in nuclear and particle physics and cosmology. It is used to predict the ratio of protons to helium atoms in the primordial universe and to search for physics beyond the Standard Model of particle physics. We eliminated loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls. As a result of this approach and the use of an in situ neutron detector, the lifetime reported here [877.7 ± 0.7 (stat) +0.4/-0.2 (sys) seconds] does not require corrections larger than the quoted uncertainties.
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Affiliation(s)
- R W Pattie
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - N B Callahan
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | - C Cude-Woods
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.,Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - E R Adamek
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | - L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - S M Clayton
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - S A Currie
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E B Dees
- Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - X Ding
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - E M Engel
- West Point Military Academy, West Point, NY 10996, USA
| | - D E Fellers
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - W Fox
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | | | - K P Hickerson
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
| | - M A Hoffbauer
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - A T Holley
- Department of Physics, Tennessee Technological University, Cookeville, TN 38505, USA
| | - A Komives
- Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135-0037, USA
| | - C-Y Liu
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | | | - M Makela
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - C L Morris
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J D Ortiz
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J Ramsey
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - D J Salvat
- Department of Physics, University of Washington, Seattle, WA 98195-1560, USA
| | - A Saunders
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - S J Seestrom
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E I Sharapov
- Joint Institute for Nuclear Research, Dubna, Moscow region 141980, Russia
| | - S K Sjue
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Z Tang
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J Vanderwerp
- Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA
| | - B Vogelaar
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - P L Walstrom
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - W Wei
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - H L Weaver
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J W Wexler
- Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - T L Womack
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - A R Young
- Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
| | - B A Zeck
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.,Triangle Universities Nuclear Laboratory and North Carolina State University, Raleigh, NC 27695, USA
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6
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Broussard LJ, Alarcon R, Baeßler S, Barrón Palos L, Birge N, Bode T, Bowman JD, Brunst T, Calarco JR, Caylor J, Chupp T, Cianciolo V, Crawford C, Dodson GW, DuBois J, Fan W, Farrar W, Fomin N, Frlež E, Fry J, Gericke MT, Glück F, Greene GL, Grzywacz RK, Gudkov V, Hendrus C, Hersman FW, Ito T, Li H, Macsai N, Makela MF, Mammei J, Mammei R, Martin J, Martinez M, McGaughey PL, Mertens S, Mirabal-Martinez J, Mueller P, Page SA, Penttilä SI, Picker R, Plaster B, Počanić D, Radford DC, Ramsey J, Rykaczewski KP, Salas-Bacci A, Scott EM, Sjue SKL, Smith A, Smith E, Sprow A, Stevens E, Wexler J, Whitehead R, Wilburn WS, Young AR, Zeck BA. Neutron decay correlations in the Nab experiment. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/876/1/012005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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7
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Morris CL, Adamek ER, Broussard LJ, Callahan NB, Clayton SM, Cude-Woods C, Currie SA, Ding X, Fox W, Hickerson KP, Hoffbauer MA, Holley AT, Komives A, Liu CY, Makela M, Pattie RW, Ramsey J, Salvat DJ, Saunders A, Seestrom SJ, Sharapov EI, Sjue SK, Tang Z, Vanderwerp J, Vogelaar B, Walstrom PL, Wang Z, Wei W, Wexler JW, Womack TL, Young AR, Zeck BA. A new method for measuring the neutron lifetime using an in situ neutron detector. Rev Sci Instrum 2017; 88:053508. [PMID: 28571423 PMCID: PMC5648580 DOI: 10.1063/1.4983578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
In this paper, we describe a new method for measuring surviving neutrons in neutron lifetime measurements using bottled ultracold neutrons (UCN), which provides better characterization of systematic uncertainties and enables higher precision than previous measurement techniques. An active detector that can be lowered into the trap has been used to measure the neutron distribution as a function of height and measure the influence of marginally trapped UCN on the neutron lifetime measurement. In addition, measurements have demonstrated phase-space evolution and its effect on the lifetime measurement.
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Affiliation(s)
- C L Morris
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E R Adamek
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - L J Broussard
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N B Callahan
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - S M Clayton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C Cude-Woods
- Triangle Universities Nuclear Laboratory, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - S A Currie
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - X Ding
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - W Fox
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - K P Hickerson
- California Institute of Technology, Pasadena, California 91125, USA
| | - M A Hoffbauer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A T Holley
- Department of Physics, Tennessee Tech University, Cookeville, Tennessee 38505, USA
| | - A Komives
- Department of Physics, DePauw University, Greencastle Indiana 46135-0037, USA
| | - C-Y Liu
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - M Makela
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R W Pattie
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Ramsey
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D J Salvat
- Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA
| | - A Saunders
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S J Seestrom
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E I Sharapov
- Joint Institute for Nuclear Research, Dubna, Moscow Region 141980, Russia
| | - S K Sjue
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Z Tang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Vanderwerp
- Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - B Vogelaar
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - P L Walstrom
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Wanchun Wei
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J W Wexler
- Triangle Universities Nuclear Laboratory, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - T L Womack
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A R Young
- Triangle Universities Nuclear Laboratory, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - B A Zeck
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Sjue SKL, Broussard LJ, Makela M, McGaughey PL, Young AR, Zeck BA. Radial distribution of charged particles in a magnetic field. Rev Sci Instrum 2015; 86:023102. [PMID: 25725818 DOI: 10.1063/1.4906547] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The radial spread of charged particles emitted from a point source in a magnetic field is a potential source of systematic error for any experiment where magnetic fields guide charged particles to detectors with finite size. Assuming uniform probability as a function of the phase along the particle's helical trajectory, an analytic solution for the radial probability distribution function follows which applies to experiments in which particles are generated throughout a volume that spans a sufficient length along the axis of a homogeneous magnetic field. This approach leads to the same result as a different derivation given by Dubbers et al., Nucl. Instrum. Methods Phys. Res., Sect. A 763, 112-119 (2014). But the constant phase approximation does not strictly apply to finite source volumes or fixed positions, which lead to local maxima in the radial distribution of emitted particles at the plane of the detector. A simple method is given to calculate such distributions, then the effect is demonstrated with data from a (207)Bi electron-conversion source in the superconducting solenoid magnet spectrometer of the Ultracold Neutron facility at the Los Alamos Neutron Science Center. Implications for neutron beta decay spectroscopy are discussed.
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Affiliation(s)
- S K L Sjue
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L J Broussard
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Makela
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - P L McGaughey
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A R Young
- North Carolina State University, Raleigh, North Carolina 27695, USA
| | - B A Zeck
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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9
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Saunders A, Makela M, Bagdasarova Y, Back HO, Boissevain J, Broussard LJ, Bowles TJ, Carr R, Currie SA, Filippone B, García A, Geltenbort P, Hickerson KP, Hill RE, Hoagland J, Hoedl S, Holley AT, Hogan G, Ito TM, Lamoreaux S, Liu CY, Liu J, Mammei RR, Martin J, Melconian D, Mendenhall MP, Morris CL, Mortensen RN, Pattie RW, Pitt M, Plaster B, Ramsey J, Rios R, Sallaska A, Seestrom SJ, Sharapov EI, Sjue S, Sondheim WE, Teasdale W, Young AR, VornDick B, Vogelaar RB, Wang Z, Xu Y. Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source. Rev Sci Instrum 2013; 84:013304. [PMID: 23387639 DOI: 10.1063/1.4770063] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code. The source is shown to perform as modeled. The maximum delivered UCN density at the exit from the biological shield is 52(9) UCN/cc with a solid deuterium volume of ~1500 cm(3).
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Affiliation(s)
- A Saunders
- Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
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Holley AT, Broussard LJ, Davis JL, Hickerson K, Ito TM, Liu CY, Lyles JTM, Makela M, Mammei RR, Mendenhall MP, Morris CL, Mortensen R, Pattie RW, Rios R, Saunders A, Young AR. A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment. Rev Sci Instrum 2012; 83:073505. [PMID: 22852693 DOI: 10.1063/1.4732822] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The UCNA collaboration is making a precision measurement of the β asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during the 2007 run cycle of the Los Alamos Neutron Science Center's 800 MeV proton accelerator is detailed. These studies determined the flipping efficiency of the device, averaged over the UCN spectrum present at the location of the spin flipper, to be ̅ε=0.9985(4).
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Affiliation(s)
- A T Holley
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
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11
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Liu J, Mendenhall MP, Holley AT, Back HO, Bowles TJ, Broussard LJ, Carr R, Clayton S, Currie S, Filippone BW, García A, Geltenbort P, Hickerson KP, Hoagland J, Hogan GE, Hona B, Ito TM, Liu CY, Makela M, Mammei RR, Martin JW, Melconian D, Morris CL, Pattie RW, Pérez Galván A, Pitt ML, Plaster B, Ramsey JC, Rios R, Russell R, Saunders A, Seestrom SJ, Sondheim WE, Tatar E, Vogelaar RB, VornDick B, Wrede C, Yan H, Young AR. Determination of the axial-vector weak coupling constant with ultracold neutrons. Phys Rev Lett 2010; 105:181803. [PMID: 21231098 DOI: 10.1103/physrevlett.105.181803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Indexed: 05/30/2023]
Abstract
A precise measurement of the neutron decay β asymmetry A₀ has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A₀ = -0.119 66±0.000 89{-0.001 40}{+0.001 23}, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon g{A}/g{V}=-1.275 90{-0.004 45}{+0.004 09}.
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Affiliation(s)
- J Liu
- Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
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12
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Pattie RW, Anaya J, Back HO, Boissevain JG, Bowles TJ, Broussard LJ, Carr R, Clark DJ, Currie S, Du S, Filippone BW, Geltenbort P, García A, Hawari A, Hickerson KP, Hill R, Hino M, Hoedl SA, Hogan GE, Holley AT, Ito TM, Kawai T, Kirch K, Kitagaki S, Lamoreaux SK, Liu CY, Liu J, Makela M, Mammei RR, Martin JW, Melconian D, Meier N, Mendenhall MP, Morris CL, Mortensen R, Pichlmaier A, Pitt ML, Plaster B, Ramsey JC, Rios R, Sabourov K, Sallaska AL, Saunders A, Schmid R, Seestrom S, Servicky C, Sjue SKL, Smith D, Sondheim WE, Tatar E, Teasdale W, Terai C, Tipton B, Utsuro M, Vogelaar RB, Wehring BW, Xu YP, Young AR, Yuan J. First measurement of the neutron beta asymmetry with ultracold neutrons. Phys Rev Lett 2009; 102:012301. [PMID: 19257182 DOI: 10.1103/physrevlett.102.012301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Indexed: 05/27/2023]
Abstract
We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.
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Affiliation(s)
- R W Pattie
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
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Lambert GP, Broussard LJ, Mason BL, Mauermann WJ, Gisolfi CV. Gastrointestinal permeability during exercise: effects of aspirin and energy-containing beverages. J Appl Physiol (1985) 2001; 90:2075-80. [PMID: 11356768 DOI: 10.1152/jappl.2001.90.6.2075] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to determine whether aspirin (A) ingestion combined with prolonged exercise increases gastrointestinal permeability and whether consumption of a carbohydrate-containing (CHO) or a CHO + glutamine-containing (CHO+G) beverage would reduce this effect. Seventeen subjects completed six experiments. They ingested A (1,300 mg) or placebo (P) pills the evening before and before running 60 min at 70% maximal oxygen uptake. Also, before running they ingested a solution containing 5 g lactulose (L), 5 g sucrose (S), and 2 g rhamnose (R). During each trial, either a 6% CHO beverage, a 6% CHO+G (0.6%; 41 mM) beverage, or a water placebo (WP) was consumed. For 4 h after a run, all urine was collected to measure urinary excretion of L, R, and S. S excretion (percentage of dose ingested; measure of gastroduodenal permeability) was significantly greater (P < 0.05) during the A trial while the subjects drank the WP compared with all other trials. Administration of A also significantly increased L/R (measure of intestinal permeability) for the CHO and WP trials compared with all P trials. Ingestion the CHO or CHO+G beverages significantly reduced S excretion and L excretion when A was administered, but it did not reduce L/R. These results indicate that gastroduodenal and intestinal permeability increase after A ingestion during prolonged running and that ingestion of a CHO beverage attenuates the gastroduodenal effect but not the intestinal effect. Furthermore, addition of G to the CHO beverage provided no additional benefit in reducing gastroduodenal or intestinal permeability.
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Affiliation(s)
- G P Lambert
- Department of Exercise Science, University of Iowa, Iowa City, Iowa 52242, USA
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