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Search Publications by: Hans Pieter Mumm (Fed)

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Displaying 26 - 48 of 48

Background Radiation Measurements at High Power Research Reactors

January 11, 2016
Author(s)
Hans P. Mumm
Research reactors typically host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons

May 1, 2014
Author(s)
Hans P. Mumm, Alan Keith Thompson, Paul R. Huffman, Christopher O'Shaughnessy, Kevin J. Coakley, Robert Golub, John M. Doyle, Steve K. Lamoreaux, P.-N. Seo, C E. Mattoni, S N. Dzhosyuk, L Yang, Grace L. Yang, Karl W. Schelhammer, Christopher M. Swank
The neutron beta-decay lifetime plays an important role, both in understanding weak interactions within the framework of the Standard Model, and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we

Search for a T-odd, P-even Triple Correlation in Neutron Decay

September 14, 2012
Author(s)
Jeffrey S. Nico, T E. Chupp, K P. Coulter, R L. Cooper, S. J. Freeman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Hans P. Mumm, Alan K. Thompson, C A. Trull, F. E. Wiefeldt, J. F. Wilkerson
Time-reversal-invariance (T) violation, or equivalently, assuming charge-conjugation-parity-time-reversal (CPT) invariance, CP violation may explain the observed cosmological baryon asymmetry as well as signal physics beyond the Standard Model. In the

A New Limit on Time-Reversal Violation in Beta Decay

September 2, 2012
Author(s)
Hans P. Mumm, T E. Chupp, K P. Coulter, R L. Cooper, S J. Freedman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Jeffrey S. Nico, Alan K. Thompson, C A. Trull, J. F. Wilkerson, F. E. Wiefeldt
We report the results of an improved determination of the triple correlation DP • (p_e × p_v) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is

A gamma and X-ray dector for cryogenic, high magnetic field applications

July 13, 2012
Author(s)
Thomas R. Gentile, R L. Cooper, R. Alarcon, M J. Bales, E J. Beise, H Breuer, J. Byrne, T E. Chupp, Kevin J. Coakley, Maynard S. Dewey, Changbo Fu, Hans P. Mumm, Jeffrey S. Nico, B. O'Neill, K. Pulliam, Alan Keith Thompson, F E. Wietfeldt
As part of an experiment to measure the spectrum of photons emitted in beta-decay of the free neu- tron, we developed and operated a detector consisting of 12 bismuth germanate (BGO) crystals coupled to avalanche photodiodes (APDs). The detector was

An Upper Bound on Parity Violating Neutron Spin Rotation in He-4

January 31, 2011
Author(s)
Jeffrey S. Nico, William M. Snow, Christopher D. Bass, Tiffany D. Bass, B. E. Crawford, K. F. Gan, B R. Heckel, D Lou, D M. Markoff, A M. Micherdzinska, Hans P. Mumm, A. K. Opper, M Sarsour, E I. Sharapov, H E. Swanson, S. C. Walbridge, V Zhumabekova
We report an upper bound on parity violating neutron spin rotation in He-4. This experiment is the most sensitive search for neutron weak optical activity yet performed. Our result for the neutron spin rotation angle per unit length in He-4 is dphi/dz = (

Polarized neutron beam properties for measuring parity-violating spin rotation in liquid He4

December 14, 2010
Author(s)
A M. Micherdzinska, C. D. Bass, T. D. Bass, K. F. Gan, D Lou, D M. Markoff, Hans Pieter Mumm, Jeffrey S. Nico, A. K. Opper, E I. Sharapov, M Snow, H E. Swanson, V Zhumabekova
Measurements of parity-violating neutron spin rotation can provide insight into the poorly nderstood nucleon-nucleon weak interaction. Because the expected rotation angle per unit length is small (10−7 rad/m), several properties of the polarized cold

An experiment for the precision measurement of the radiative decay mode of the neutron

October 5, 2009
Author(s)
R Cooper, Christopher D. Bass, E Beise, H Breuer, Jim Byrne, T E. Chupp, Kevin Coakley, Maynard S. Dewey, B Fisher, Changbo Fu, Thomas R. Gentile, M. McGonagle, Hans Pieter Mumm, Jeffrey S. Nico, Alan Keith Thompson, F E. Wietfeldt
The neutron typically beta decays into a proton, electron, and antineutrino. In some decays, it can be accompanied by a high energy photon. We recently performed the rst observation of the radiative beta decay branch for the free neutron with photons of

Radiative Beta Decay of the Free Neutron

February 2, 2009
Author(s)
R L. Cooper, T E. Chupp, Maynard S. Dewey, Thomas R. Gentile, Hans Pieter Mumm, Jeffrey S. Nico, Alan Keith Thompson, B M. Fisher, I Kremsky, F E. Wietfeldt, E J. Beise, H Breuer, K G. Kiriluk, J Bryne, Kevin Coakley, Changbo Fu
The theory of quantum electrodynamics predicts that the beta decay of the neutron into a proton, electron, and antineutrino is accompanied by a continuous spectrum of emitted photons described as inner bremsstrahlung. While this phenomenon has been

Particle and Photon Detection for a Neutron Radiative Decay Experiment

April 11, 2007
Author(s)
Thomas R. Gentile, Maynard S. Dewey, Hans P. Mumm, Jeffrey S. Nico, Alan K. Thompson, T E. Chupp, R Cooper, B M. Fisher, I Kremsky, F E. Wietfeldt, K G. Kiriluk, E Beise
We present the particle and photon detection methods employed in a program to observe neutron radiative beta-decay. The experiment is located at the NG-6 beam line at the National Institute of Standards and Technology Center for Neutron Research. Electrons

Observation of the Radiative Decay Mode of the Free Neutron

December 29, 2006
Author(s)
Jeffrey S. Nico, Maynard S. Dewey, Thomas R. Gentile, Hans P. Mumm, Alan K. Thompson, B Fisher, I Kremsky, Fred E. Wietfeldt, T E. Chupp, R Cooper, E Beise, K G. Kiriluk, J Byrne, Kevin J. Coakley
The theory of quantum electrodynamics predicts that beta decay of the neutron into a proton, electron, and antineutrino should be accompanied by a continuous spectrum of soft photons. While this inner bremsstrahlung branch has been previously measured in

Progress Towards a Precision Measurement of the Neutron Lifetime Using Magnetically Trapped Ultracold Neutrons

January 1, 2006
Author(s)
P.-N. Seo, Kevin Coakley, J M. Doyle, F H. DuBose, R Golub, E Korobkina, S K. Lamoreaux, Hans Pieter Mumm, C M. O'Shaughnessy, G R. Palmquis, A K. Thompson, Grace L. Yang, L Yang, Paul R. Huffman
As part of an on-going program utilizing magnetically trapped ultracold neutrons (UCNs,) we are developing a technique that offers the possibility of improving the precision of the neutron lifetime by more than an order of magnitude. The experiment works

Radiative Decay Mode of the Free Neutron

January 1, 2006
Author(s)
Jeffrey S. Nico, Maynard S. Dewey, Thomas R. Gentile, Hans P. Mumm, Alan K. Thompson, B M. Fisher, I Kremsky, Fred E. Wietfeldt, T E. Chupp, R L. Cooper, E J. Beise, K G. Kiriluk, J Byrne, K Coakley

Testing Time-Reversal Symmetry in Neutron Beta Decay

January 1, 2005
Author(s)
Hans P. Mumm, Maynard S. Dewey, Jeffrey S. Nico, Alan K. Thompson, A Garcia, J F. Wilkerson, S J. Freedman, B K. Fujikawa, T E. Chupp, R L. Cooper, C A. Trull, Fred E. Wietfeldt, G L. Jones

Large-Area TKIDs for a New Generation of Neutron Beta Decay Experiments

January 1, 2001
Author(s)
Elizabeth Scott, Jimmy P. Caylor, Maynard S. Dewey, Jiansong Gao, Colin A. Heikes, Shannon Hoogerheide, Hans Pieter Mumm, Jeffrey S. Nico, Joel Ullom, Michael Vissers
Nuclear physics has long played a central role in our efforts to better understand the natural world. Several experiments are well positioned to improve limits in searches for physics Beyond the Standard Model (BSM). Many of the experiments in nuclear

New Limit on the D Coefficient in Polarized Neutron Decay

January 1, 2000
Author(s)
L Lising, S R. Hwang, J M. Adams, T J. Bowles, M C. Browne, T E. Chupp, K A. Coulterpark, Maynard S. Dewey, S J. Freedman, B K. Fujikawa, A Garcia, G L. Greene, G L. Jones, Hans P. Mumm, Jeffrey S. Nico, J M. Richardson, R G. Robertson, W A. Teasdale, Alan K. Thompson, E G. Wasserman, Fred E. Wietfeldt, R C. Welsh, J F. Wilkerson

Time Reversal in Polarized Neutron Decay - The emiT Experiment

January 1, 2000
Author(s)
G L. Jones, J M. Adams, J M. Anaya, T J. Bowles, T E. Chupp, K A. Coulterpark, Maynard S. Dewey, S J. Freedman, B K. Fujikawa, A Garcia, G L. Greene, S -. Hwang, L Lising, Hans Pieter Mumm, Jeffrey S. Nico, R G. Robertson, T D. Steiger, W A. Teasdale, Alan Keith Thompson, E G. Wasserman, Fred E. Wietfeldt, J F. Wilkerson