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Nuclear

Robert W. Pattie Jr.

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Full-Text Articles in Physics

Search For The Neutron Decay N → X + Γ , Where X Is A Dark Matter Particle, Zhoawen Tang, Marie Blatnik, Leah J. Broussard, J. H. Choi, Stephen M. Clayton, Christopher Cude-Woods, Scott Currie, D. E. Fellers, E. M. Fries, Peter Geltenbort, F. Gonzalez, Kevin P. Hickerson, Takeyasu M. Ito, Chen Y. Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, C. M. O'Shaughnessy, Robert W. Pattie Jr., Bradley R. Plaster, D. J. Salvat, Alexander Saunders, Zhehui Wang, Albert R. Young, B. A. Zeck Jul 2018

Search For The Neutron Decay N → X + Γ , Where X Is A Dark Matter Particle, Zhoawen Tang, Marie Blatnik, Leah J. Broussard, J. H. Choi, Stephen M. Clayton, Christopher Cude-Woods, Scott Currie, D. E. Fellers, E. M. Fries, Peter Geltenbort, F. Gonzalez, Kevin P. Hickerson, Takeyasu M. Ito, Chen Y. Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, C. M. O'Shaughnessy, Robert W. Pattie Jr., Bradley R. Plaster, D. J. Salvat, Alexander Saunders, Zhehui Wang, Albert R. Young, B. A. Zeck

Robert W. Pattie Jr.

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 …

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Search For Dark Matter Decay Of The Free Neutron From The Ucna Experiment: N → Χ + E^+E^−, Xiaohui Sun, Edith Adamek, Bruno Allgeier, Matthias A. Blatnik, Thomas J. Bowles, Leah J. Broussard, Matthew A. Brown, Richard Carr, Steven M. Clayton, Chris Cude-Woods, Sonja Currie, Eric B. Dees, Xingxing Ding, Bradley W. Filippone, A. Bello García, Peter Geltenbort, Salajeghe Hasan, Kevin P. Hickerson, J. Todd Hoagland, R. Hong, Gary E. Hogan, Anthony T. Holley, Takeyasu M. Ito, Amanda L. Knecht, Chao-Yu Liu, Jingyang Liu, María Makela, Russel Mammei, J. W. Martin, Dan Melconian, Michael P. Mendenhall, Stephen D. Moore, Charles L. Morris, Sushil Nepal, N. Vahedi Nouri, Robert W. Pattie Jr., A. Pérez Galván, David G. Phillips, Richard H. Picker, Margaret L. Pitt, Blakely A. Plaster, Jana C. Ramsey, R. Barreto Rios, Daniel J. Salvat, Andy Saunders, Walter Sondheim, S. Sjue, Steven Slutsky, Charles Swank, Gyani Swift, E. Tatar, R. Bruce Vogelaar, Brittany Vorndick, Z. Wang, Wanchun Wei, J. Wexler, T. Womack, Christopher Wrede, Andrew R. Young, B. A. Zeck May 2018

Search For Dark Matter Decay Of The Free Neutron From The Ucna Experiment: N → Χ + E^+E^−, Xiaohui Sun, Edith Adamek, Bruno Allgeier, Matthias A. Blatnik, Thomas J. Bowles, Leah J. Broussard, Matthew A. Brown, Richard Carr, Steven M. Clayton, Chris Cude-Woods, Sonja Currie, Eric B. Dees, Xingxing Ding, Bradley W. Filippone, A. Bello García, Peter Geltenbort, Salajeghe Hasan, Kevin P. Hickerson, J. Todd Hoagland, R. Hong, Gary E. Hogan, Anthony T. Holley, Takeyasu M. Ito, Amanda L. Knecht, Chao-Yu Liu, Jingyang Liu, María Makela, Russel Mammei, J. W. Martin, Dan Melconian, Michael P. Mendenhall, Stephen D. Moore, Charles L. Morris, Sushil Nepal, N. Vahedi Nouri, Robert W. Pattie Jr., A. Pérez Galván, David G. Phillips, Richard H. Picker, Margaret L. Pitt, Blakely A. Plaster, Jana C. Ramsey, R. Barreto Rios, Daniel J. Salvat, Andy Saunders, Walter Sondheim, S. Sjue, Steven Slutsky, Charles Swank, Gyani Swift, E. Tatar, R. Bruce Vogelaar, Brittany Vorndick, Z. Wang, Wanchun Wei, J. Wexler, T. Womack, Christopher Wrede, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle (χ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single χalong with an e+e− pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with ∼4π acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy …

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Performance Of The Upgraded Ultracold Neutron Source At Los Alamos National Laboratory And Its Implication For A Possible Neutron Electric Dipole Moment Experiment, Takeyasu M. Ito, Evan R. Adamek, Nathan B. Callahan, J. H. Choi, Stephen M. Clayton, Chris Cude-Woods, Scott Currie, Xinjian Ding, D. E. Fellers, Peter Geltenbort, Steve K. Lamoreaux, C. Y. Liu, S. Macdonald, Mark Makela, Charles L. Morris, Robert W. Pattie Jr., John Clinton Ramsey, Daniel J. Salvat, Andy Saunders, Edward I. Sharapov, S. Sjue, A. P. Sprow, Zebo Tang, H. L. Weaver, Wanchun Wei, Andrew R. Young Jan 2018

Performance Of The Upgraded Ultracold Neutron Source At Los Alamos National Laboratory And Its Implication For A Possible Neutron Electric Dipole Moment Experiment, Takeyasu M. Ito, Evan R. Adamek, Nathan B. Callahan, J. H. Choi, Stephen M. Clayton, Chris Cude-Woods, Scott Currie, Xinjian Ding, D. E. Fellers, Peter Geltenbort, Steve K. Lamoreaux, C. Y. Liu, S. Macdonald, Mark Makela, Charles L. Morris, Robert W. Pattie Jr., John Clinton Ramsey, Daniel J. Salvat, Andy Saunders, Edward I. Sharapov, S. Sjue, A. P. Sprow, Zebo Tang, H. L. Weaver, Wanchun Wei, Andrew R. Young

Robert W. Pattie Jr.

The ultracold neutron (UCN) source at Los Alamos National Laboratory (LANL), which uses solid deuterium as the UCN converter and is driven by accelerator spallation neutrons, has been successfully operated for over 10 years, providing UCN to various experiments, as the first production UCN source based on the superthermal process. It has recently undergone a major upgrade. This paper describes the design and performance of the upgraded LANL UCN source. Measurements of the cold neutron spectrum and UCN density are presented and compared to Monte Carlo predictions. The source is shown to perform as modeled. The UCN density measured at …

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First Direct Constraints On Fierz Interference In Free-Neutron Β Decay, Kevin P. Hickerson, Xiaohui Sun, Yelena Bagdasarova, David Bravo-Berguño, Leah J. Broussard, Peter Brown, Richard Carr, Scott Currie, Xinjian Ding, Bradley W. Filippone, Alejandro García, Peter Geltenbort, J. Todd Hoagland, A. T. Holley, Ran Hong, Takeyasu M. Ito, Andreas Knecht, Chao-Yu Liu, Jiang-Lai Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Dan Melconian, Michael P. Mendenhall, Spencer D. Moore, Christopher L. Morris, Robert W. Pattie, A. Pérez Galván, Ruediger Picker, Margaret L. Pitt, Bradley R. Plaster, John C. Ramsey, Roger H. Rios, A. Saunders, Susan J. Seestrom, Eduard I. Sharapov, Walter E. Sondheim, Erdinch Tatar, R. Bruce Vogelaar, Brittney Vorndick, Christopher Wrede, Andrew R. Young, B. A. Zeck Nov 2017

First Direct Constraints On Fierz Interference In Free-Neutron Β Decay, Kevin P. Hickerson, Xiaohui Sun, Yelena Bagdasarova, David Bravo-Berguño, Leah J. Broussard, Peter Brown, Richard Carr, Scott Currie, Xinjian Ding, Bradley W. Filippone, Alejandro García, Peter Geltenbort, J. Todd Hoagland, A. T. Holley, Ran Hong, Takeyasu M. Ito, Andreas Knecht, Chao-Yu Liu, Jiang-Lai Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Dan Melconian, Michael P. Mendenhall, Spencer D. Moore, Christopher L. Morris, Robert W. Pattie, A. Pérez Galván, Ruediger Picker, Margaret L. Pitt, Bradley R. Plaster, John C. Ramsey, Roger H. Rios, A. Saunders, Susan J. Seestrom, Eduard I. Sharapov, Walter E. Sondheim, Erdinch Tatar, R. Bruce Vogelaar, Brittney Vorndick, Christopher Wrede, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

Precision measurements of free-neutron β decay have been used to precisely constrain our understanding of the weak interaction. However, the neutron Fierz interference term bn, which is particularly sensitive to beyond-standard-model tensor currents at the TeV scale, has thus far eluded measurement. Here we report the first direct constraints on this term, finding bn=0.067±0.005stat+0.090−0.061sys, consistent with the standard model. The uncertainty is dominated by absolute energy reconstruction and the linearity of the β spectrometer energy response.

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The Upscattering Of Ultracold Neutrons From The Polymer (C6h12)N, Eduard I. Sharapov, Christopher L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Leah J. Broussard, Chris B. Cude-Woods, Deion E. Fellers, Peter Geltenbort, Monika Hartl, Siraj I. Hasan, Kevin P. Hickerson, Gary E. Hogan, Anthony T. Holley, C. M. Lavelle, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie, David G. Phillips, John Ramsey, Daniel J. Salvat, Susan J. Seestrom, Erik Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck Dec 2013

The Upscattering Of Ultracold Neutrons From The Polymer (C6h12)N, Eduard I. Sharapov, Christopher L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Leah J. Broussard, Chris B. Cude-Woods, Deion E. Fellers, Peter Geltenbort, Monika Hartl, Siraj I. Hasan, Kevin P. Hickerson, Gary E. Hogan, Anthony T. Holley, C. M. Lavelle, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie, David G. Phillips, John Ramsey, Daniel J. Salvat, Susan J. Seestrom, Erik Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

It is generally accepted that the main cause of ultracold neutron (UCN) losses in storage traps is upscattering to the thermal energy range by hydrogen adsorbed on the surface of the trap walls. However, the data on which this conclusion is based are poor and contradictory. Here we report a measurement, performed at the Los Alamos National Laboratory UCN source, of the average energy of the flux of upscattered neutrons after the interaction of UCN with hydrogen bound in the semicrystalline polymer PMP (trade name TPX), [C6H12]n. Our analysis, performed with the mcnp code which applies …

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Limits On Tensor Coupling From Neutron Β Decay, Robert W. Pattie, Kevin P. Hickerson, Andrew R. Young Oct 2013

Limits On Tensor Coupling From Neutron Β Decay, Robert W. Pattie, Kevin P. Hickerson, Andrew R. Young

Robert W. Pattie Jr.

Limits on the tensor couplings generating a Fierz interference term b in mixed Gamow-Teller Fermi decays can be derived by combining data from measurements of angular correlation parameters in neutron decay, the neutron lifetime, and GV=GFVud as extracted from measurements of the Ftvalues from the 0+→0+ superallowed decay data set. These limits are derived by comparing the neutron β-decay rate as predicted in the standard model with the measured decay rate while allowing for the existence of beyond the standard model (BSM) couplings. We analyze limits derived from …

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Measurements Of Ultracold Neutron Upscattering And Absorption In Polyethylene And Vanadium, Eduard I. Sharapov, Charles L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Yelena Bagdasarova, Leah J. Broussard, Chris Cude-Woods, Deon E. Fellers, Peter Geltenbort, Siraj I. Hasan, Kevin P. Hickerson, Gary Hogan, Anthony T. Holley, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie Jr., David G. Phillips, John Ramsey, D. J. Salvat, Susan J. Seestrom, E. Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck Sep 2013

Measurements Of Ultracold Neutron Upscattering And Absorption In Polyethylene And Vanadium, Eduard I. Sharapov, Charles L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Yelena Bagdasarova, Leah J. Broussard, Chris Cude-Woods, Deon E. Fellers, Peter Geltenbort, Siraj I. Hasan, Kevin P. Hickerson, Gary Hogan, Anthony T. Holley, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie Jr., David G. Phillips, John Ramsey, D. J. Salvat, Susan J. Seestrom, E. Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

The study of neutron cross sections for elements used as efficient “absorbers” of ultracold neutrons (UCN) is crucial for many precision experiments in nuclear and particle physics, cosmology and gravity. In this context, “absorption” includes both the capture and upscattering of neutrons to the energies above the UCN energy region. The available data, especially for hydrogen, do not agree between themselves or with the theory. In this report we describe measurements performed at the Los Alamos National Laboratory UCN facility of the UCN upscattering cross sections for vanadium and for hydrogen in CH2 using simultaneous measurements of the radiative …

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Project X: Physics Opportunities, Andreas S. Kronfeld, Robert S. Tschirhart, Usama Al-Binni, Wolfgang Altmannshofer, Charles Ankenbrandt, Kaladi Babu, Sunanda Banerjee, Matthew Bass, Brian Batell, David V. Baxter, Zurab Berezhiani, Marc Bergevin, Robert Bernstein, Sudeb Bhattacharya, Mary Bishai, Thomas Blum, S. Alex Bogacz, Stephen J. Brice, Joachim Brod, Alan Bross, Michael Buchoff, Thomas W. Burgess, Marcela Carena, Luis A. Castellanos, Subhasis Chattopadhyay, Mu-Chun Chen, Daniel Cherdack, Norman H. Christ, Tim Chupp, Vincenzo Cirigliano, Pilar Coloma, Christopher E. Coppola, Ramanath Cowsik, J. Allen Crabtree, André De Gouvêa, Jean-Pierre Delahaye, Dmitri Denisov, Patrick Deniverville, Ranjan Dharmapalan, Alexander Dolgov, Georgi Dvali, Estia Eichten, Jürgen Engelfried, Phillip D. Ferguson, Tony Gabriel, Avraham Gal, Franz Gallmeier, Kenneth S. Ganezer, Susan Gardner Jul 2013

Project X: Physics Opportunities, Andreas S. Kronfeld, Robert S. Tschirhart, Usama Al-Binni, Wolfgang Altmannshofer, Charles Ankenbrandt, Kaladi Babu, Sunanda Banerjee, Matthew Bass, Brian Batell, David V. Baxter, Zurab Berezhiani, Marc Bergevin, Robert Bernstein, Sudeb Bhattacharya, Mary Bishai, Thomas Blum, S. Alex Bogacz, Stephen J. Brice, Joachim Brod, Alan Bross, Michael Buchoff, Thomas W. Burgess, Marcela Carena, Luis A. Castellanos, Subhasis Chattopadhyay, Mu-Chun Chen, Daniel Cherdack, Norman H. Christ, Tim Chupp, Vincenzo Cirigliano, Pilar Coloma, Christopher E. Coppola, Ramanath Cowsik, J. Allen Crabtree, André De Gouvêa, Jean-Pierre Delahaye, Dmitri Denisov, Patrick Deniverville, Ranjan Dharmapalan, Alexander Dolgov, Georgi Dvali, Estia Eichten, Jürgen Engelfried, Phillip D. Ferguson, Tony Gabriel, Avraham Gal, Franz Gallmeier, Kenneth S. Ganezer, Susan Gardner

Robert W. Pattie Jr.

Part 2 of "Project X: Accelerator Reference Design, Physics Opportunities, Broader Impacts". In this Part, we outline the particle-physics program that can be achieved with Project X, a staged superconducting linac for intensity-frontier particle physics. Topics include neutrino physics, kaon physics, muon physics, electric dipole moments, neutron-antineutron oscillations, new light particles, hadron structure, hadron spectroscopy, and lattice-QCD calculations. Part 1 is available as arXiv:1306.5022 [physics.acc-ph] and Part 3 is available as arXiv:1306.5024 [physics.acc-ph].

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Precision Measurement Of The Neutron Beta-Decay Asymmetry, Michael P. Mendenhall, Robert W. Pattie, Yelena Bagdasarova, David B. Berguno, Leah J. Broussard, Richard Carr, Scott Currie, Xinjian Ding, Bradley W. Filippone, Alejandro Garcia, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Ran Hong, Takeyasu M. Ito, Andreas Knecht, Chenyu Liu, J. L. Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Dan Melconian, Spencer D. Moore, Christopher L. Morris, Margaret L. Pitt, Blakely Plaster, John C. Ramsey, Roger Rios, Andy Saunders, Susan J. Seestrom, Eduard I. Sharapov, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Andrew R. Young, B. A. Zeck Mar 2013

Precision Measurement Of The Neutron Beta-Decay Asymmetry, Michael P. Mendenhall, Robert W. Pattie, Yelena Bagdasarova, David B. Berguno, Leah J. Broussard, Richard Carr, Scott Currie, Xinjian Ding, Bradley W. Filippone, Alejandro Garcia, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Ran Hong, Takeyasu M. Ito, Andreas Knecht, Chenyu Liu, J. L. Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Dan Melconian, Spencer D. Moore, Christopher L. Morris, Margaret L. Pitt, Blakely Plaster, John C. Ramsey, Roger Rios, Andy Saunders, Susan J. Seestrom, Eduard I. Sharapov, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

A new measurement of the neutron β-decay asymmetry A0 has been carried out by the UCNA collaboration using polarized ultracold neutrons (UCN) from the solid deuterium UCN source at the Los Alamos Neutron Science Center (LANSCE). Improvements in the experiment have led to reductions in both statistical and systematic uncertainties leading to A0 = −0.11954(55)stat.(98)syst., corresponding to the ratio of axial-vector to vector coupling λ ≡ gA/gV = −1.2756(30). 

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Performance Of The Los Alamos National Laboratory Spallation-Driven Solid-Deuterium Ultra-Cold Neutron Source, Andrew Saunders, Mark Makela, Yelena Bagdasarova, Henning O. Back, J. Boissevain, Leah J. Broussard, Thomas J. Bowles, R. Carr, Scott A. Currie, Bradley Filippone, A. García, Peter Geltenbort, Kevin P. Hickerson, R. E. Hill, J. Todd Hoagland, S. Hoedl, Anthony T. Holley, Gary E. Hogan, Takeyasu M. Ito, Steve Lamoreaux, Chen-Yu Liu, J. Liu, Russell R. Mammei, J. Martin, Dan Melconian, Michael P. Mendenhall, Charles L. Morris, R. N. Mortensen, Robert W. Pattie, Margaret Pitt, Bradley Plaster, John Ramsey, R. Rios, A. Sallaska, Susan J. Seestrom, E. I. Sharapov, Sky Sjue, Walter E. Sondheim, W. Teasdale, Andrew R. Young, Brittany Vorndick, Robert B. Vogelaar, Zhehui Wang, Yanping Xu Dec 2012

Performance Of The Los Alamos National Laboratory Spallation-Driven Solid-Deuterium Ultra-Cold Neutron Source, Andrew Saunders, Mark Makela, Yelena Bagdasarova, Henning O. Back, J. Boissevain, Leah J. Broussard, Thomas J. Bowles, R. Carr, Scott A. Currie, Bradley Filippone, A. García, Peter Geltenbort, Kevin P. Hickerson, R. E. Hill, J. Todd Hoagland, S. Hoedl, Anthony T. Holley, Gary E. Hogan, Takeyasu M. Ito, Steve Lamoreaux, Chen-Yu Liu, J. Liu, Russell R. Mammei, J. Martin, Dan Melconian, Michael P. Mendenhall, Charles L. Morris, R. N. Mortensen, Robert W. Pattie, Margaret Pitt, Bradley Plaster, John Ramsey, R. Rios, A. Sallaska, Susan J. Seestrom, E. I. Sharapov, Sky Sjue, Walter E. Sondheim, W. Teasdale, Andrew R. Young, Brittany Vorndick, Robert B. Vogelaar, Zhehui Wang, Yanping Xu

Robert W. Pattie Jr.

In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultracold 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 …

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A High-Field Adiabatic Fast Passage Ultracold Neutron Spin Flipper For The Ucna Experiment, Anthony T. Holley, Leah J. Broussard, J. L. Davis, Kevin Hickerson, Takeyasu M. Ito, Chenyu Liu, J. T. M. Lyles, Mark Makela, Russell R. Mammei, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Roger Rios, Andy Saunders, Andrew R. Young Jun 2012

A High-Field Adiabatic Fast Passage Ultracold Neutron Spin Flipper For The Ucna Experiment, Anthony T. Holley, Leah J. Broussard, J. L. Davis, Kevin Hickerson, Takeyasu M. Ito, Chenyu Liu, J. T. M. Lyles, Mark Makela, Russell R. Mammei, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Roger Rios, Andy Saunders, Andrew R. Young

Robert W. Pattie Jr.

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 …

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Determination Of The Axial-Vector Weak Coupling Constant With Ultracold Neutrons., J. Liu, Michael P. Mendenhall, Anthony T. Holley, Henning O. Back, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Stephen Clayton, Scott Currie, Bradley W. Filippone, A. Garcı́A, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Takeyasu M. Ito, Chenyu Liu, Mark Makela, Russell R. Mammei, J.W. Martin, Daneil Melconian, Charles L. Morris, Robert W. Pattie, A. Pérez Galván, Margaret L. Pitt, Bradley Plaster, John C. Ramsey, R. Rios, R. Russell, Andy Saunders, Susan J. Seestrom, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, H. Yan, Albert R. Young Oct 2010

Determination Of The Axial-Vector Weak Coupling Constant With Ultracold Neutrons., J. Liu, Michael P. Mendenhall, Anthony T. Holley, Henning O. Back, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Stephen Clayton, Scott Currie, Bradley W. Filippone, A. Garcı́A, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Takeyasu M. Ito, Chenyu Liu, Mark Makela, Russell R. Mammei, J.W. Martin, Daneil Melconian, Charles L. Morris, Robert W. Pattie, A. Pérez Galván, Margaret L. Pitt, Bradley Plaster, John C. Ramsey, R. Rios, R. Russell, Andy Saunders, Susan J. Seestrom, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, H. Yan, Albert R. Young

Robert W. Pattie Jr.

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=−0.11966±0.00089+0.00123−0.00140, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon gA/gV=−1.27590+0.00409−0.00445.

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