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Selected Works of Robert W. Pattie Jr.
Article
Neutron-Antineutron Oscillations: Theoretical Status and Experimental Prospects
Physics Reports (2016)
  • David G. Phillips, North Carolina State University
  • William M. Snow, Indiana University
  • Kaladi Babu, Oklahoma State University–Stillwater
  • S. Banerjee, Saha Institute of Nuclear Physics
  • David V. Baxter, Indiana University
  • Zurab Berezhiani, Istituto Nazionale de Fisica Nucleare
  • Marc Bergevin, University of California, Davis
  • Satyaki Bhattacharya, Saha Institute of Nuclear Physics
  • Gustaaf Brooijmans, Columbia University
  • Luis Castellanos, California State University, Dominguez Hills
  • Mark C. Chen, University of California, Irvine
  • C.E. Coppola, University of Tennessee
  • Ramanath K. Cowsik, University of Washington
  • J.A. Crabtree, Oak Ridge National Laboratory
  • Pragya Das, Variable Energy Cyclotron Centre
  • Eric Dees, North Carolina State University
  • Aleksander D. Dolgov, Novosibirsk State University
  • Phillip D. Ferguson, Oak Ridge National Laboratory
  • Matthew Frost, University of Tennessee
  • Tony A. Gabriel, University of Tennessee
  • A. Gal, Hebrew University of Jerusalem
  • Franz X. Gallmeier, Oak Ridge National Laboratory
  • Kenneth S. Ganezer, California State University, Dominguez Hills
  • E. Golubeva, Russian Academy of Sciences
  • Geoffrey L. Greene, University of Tennessee
  • B. Hartfiel, California State University, Dominguez Hills
  • Ayman Hawari, North Carolina State University
  • Lawrence H. Heilbronn, University of Tennessee
  • Colin D. Johnson, Indiana University
  • Yu A Kamyshkov, University of Tennessee
  • Boris O. Kerbikov, Moscow Institute of Physics and Technology
  • Masaaki Kitaguchi, Nagoya University
  • B.Z. Kopeliovich, Valparaiso University
  • V.B. Kopeliovich, Moscow Institute of Physics and Technology
  • Vadim A. Kuzmin, Russian Academy of Sciences
  • ChenYu Liu, Indiana University
  • P. McGaughey, Los Alamos National Laboratory
  • M. Mocko, Los Alamos National Laboratory
  • Rabindra N. Mohapatra, University of Maryland, College Park
  • Nikolai V. Mokhov, Fermilab
  • Guenter Muhrer, Los Alamos National Laboratory
  • H.P. Pieter Mumm, National Institute of Standards and Technology
  • Lev B. Okun, Alikhanov Institute for Theoretical and Experimental Physics
  • Robert W. Pattie, North Carolina State University
  • C. Quigg, Fermi National Accelerator Laboratory
  • E. Ramberg, Fermilab
  • A. Ray, California State University
  • A. Roy, Inter University Accelerator Centre
  • A. Ruggles, California State University
  • U. Sarkar, Physical Research Laboratory
  • Andy Saunders, Los Alamos National Laboratory
  • A. P. Serebrovv, St. Petersburg Nuclear Physics Institute
  • H. M. Shimizu, Nagoya University
  • R. Shrock, Stony Brook University
  • A. K. Sikdara, Inter University Accelerator Centre
  • Sky Sjue, Los Alamos National Laboratory
  • S. Striganov, Fermilab
  • L. W. Townsend, California State University
  • R. Tschirhart, Fermilab
  • A. Vainshtein, California State University
  • R Van Kooten, Indiana University
  • Z. Wang, Los Alamos National Laboratory
  • A. R Young, North Carolina State University
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Abstract
The observation of neutrons turning into antineutrons would constitute a discovery of fundamental importance for particle physics and cosmology. Observing the n–n̄ transition would show that baryonnumber (B) is violated by two units and that matter containing neutrons is unstable. It would provide a clue to how the matter in our universe might have evolved from the B=0 early universe. If seen at rates observable in foreseeable next-generation experiments, it might well help us understand the observed baryon asymmetry of the universe. A demonstration of the violation of B–L by 2 units would have a profound impact on our understanding of phenomena beyond the Standard Model of particle physics.
Slow neutrons have kinetic energies of a few meV. By exploiting new slow neutron sources and optics technology developed for materials research, an optimized search for oscillations using free neutrons from a slow neutron moderator could improve existing limits on the free oscillation probability by at least three orders of magnitude. Such an experiment would deliver a slow neutron beam through a magnetically-shielded vacuum chamber to a thin annihilation target surrounded by a low-background antineutron annihilation detector. Antineutron annihilation in a target downstream of a free neutron beam is such a spectacular experimental signature that an essentially background-free search is possible. An authentic positive signal can be extinguished by a very small change in the ambient magnetic field in such an experiment. It is also possible to improve the sensitivity of neutron oscillation searches in nuclei using large underground detectors built mainly to search for proton decay and detect neutrinos.
This paper summarizes the relevant theoretical developments, outlines some ideas to improve experimental searches for free neutron oscillations, and suggests avenues both for theoretical investigation and for future improvement in the experimental sensitivity.
Keywords
  • Neutron–antineutron oscillation,
  • Baryon number violation,
  • Spallation,
  • Cold neutron source,
  • Quasi-free condition
Disciplines
Publication Date
February 11, 2016
DOI
10.1016/j.physrep.2015.11.001
Publisher Statement
This document is an author manuscript from arXiv. The publisher's final edited version of this article is available at Physics Reports.
Citation Information
David G. Phillips, William M. Snow, Kaladi Babu, S. Banerjee, et al.. "Neutron-Antineutron Oscillations: Theoretical Status and Experimental Prospects" Physics Reports Vol. 612 (2016) p. 1 - 45 ISSN: 0370-1573
Available at: http://works.bepress.com/robert-pattie/16/