Search for neutron-antineutron oscillations using multiprong events in Soudan 2
Creators
- 1. Tufts University, Medford, Massachusetts 02155 (United States)
- 2. Department of Physics, University of Oxford, Oxford OX1 3RH (United Kingdom)
- 3. Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)
- 4. Argonne National Laboratory, Argonne, Illinois 60439 (United States)
Description
We have searched for neutron-antineutron oscillations using the 5.56 fiducial kiloton-year exposure of the Soudan 2 iron tracking calorimeter. We require candidate nn(bar sign) occurrences to have ≥4 prongs (tracks and showers) and to have kinematics compatible with n(bar sign)N annihilation within a nucleus. We observe five candidate events, with an estimated background from atmospheric neutrino and cosmic ray induced events of 4.5±1.2 events. Previous experiments with smaller exposures observed no candidates, with estimated background rates similar to this experiment. We set a lifetime lower limit at 90% C.L. for the nn(bar sign) oscillation time in iron: TA(Fe)>7.2x1031 yr. The corresponding lower limit for oscillation of free neutrons is τnn-bar>1.3x108 sec
Additional details
Identifiers
- DOI
- 10.1103/PhysRevD.66.032004;
- arXiv
- arXiv:hep-ex/0205093v1;
Publishing Information
- Journal Title
- Physical Review. D, Particles Fields
- Journal Volume
- 66
- Journal Issue
- 3
- Journal Page Range
- p. 032004-032004.11
- ISSN
- 0556-2821
- CODEN
- PRVDAQ
INIS
- Country of Publication
- United States
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 35067482
- Subject category
- S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
- Descriptors DEI
- ANNIHILATION; ANTINEUTRONS; IRON; NEUTRINOS; NEUTRON-NEUTRON INTERACTIONS; OSCILLATIONS; PARTICLE KINEMATICS; QUANTUM ELECTRODYNAMICS; SHOWER COUNTERS; STANDARD MODEL; SUPERSYMMETRY
- Descriptors DEC
- ANTIBARYONS; ANTIMATTER; ANTINUCLEONS; ANTIPARTICLES; BARYON-BARYON INTERACTIONS; BARYONS; ELECTRODYNAMICS; ELEMENTARY PARTICLES; ELEMENTS; FERMIONS; FIELD THEORIES; GRAND UNIFIED THEORY; HADRON-HADRON INTERACTIONS; HADRONS; INTERACTIONS; LEPTONS; MASSLESS PARTICLES; MATHEMATICAL MODELS; MATTER; MEASURING INSTRUMENTS; METALS; NEUTRONS; NUCLEON-NUCLEON INTERACTIONS; NUCLEONS; PARTICLE INTERACTIONS; PARTICLE MODELS; QUANTUM FIELD THEORY; RADIATION DETECTORS; SYMMETRY; TRANSITION ELEMENTS; UNIFIED GAUGE MODELS
Optional Information
- Notes
- (c) 2002 The American Physical Society