No 17 keV neutrino: Admixture [lt]0. 073% (95% C. L. )

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.47.4840· OSTI ID:6771219

Ohshima, T; Sakamoto, H; Sato, T; Shirai, J; Tsukamoto, T ^[1]; Sugaya, Y; Takahashi, K ^[2]; Suzuki, T ^[3]; Rosenfeld, C; Wilson, S ^[4]; Ueno, K ^[5]; Yonezawa, Y ^[6]; Kawakami, H; Kato, S; Shibata, S; Ukai, K ^[7]

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1. KEK, National Laboratory for High Energy Physics, Tsukuba 305 (Japan)
2. Tokyo University of Agriculture and Technology, Tokyo 184 (Japan)
3. RIKEN, Institute of Physical and Chemical Research, Wako 351-01 (Japan)
4. University of South Carolina, Columbia, South Carolina 29208 (United States)
5. University of Rochester, Rochester, New York 14627 (United States)
6. Institute of Applied Physics, University of Tsukuba, Tsukuba 305 (Japan)
7. Institute for Nuclear Study, The University of Tokyo, Tokyo 188 (Japan)

To solve the controversial issue concerning the possible existence of a 17 keV neutrino with a 1% admixture in nuclear [beta] decay, we searched directly for any evidence of a production-threshold effect. The [sup 63]Ni [beta] spectrum was measured with a magnetic spectrometer, with very high statistics along with a fine energy scan over a narrow energy region around the expected threshold. The obtained mixing strength was [vert bar][ital U][vert bar][sup 2]=[[minus]0.011[plus minus]0.033(stat)[plus minus]0.030(syst)]%, very consistent with zero, and decisively excluding the existence of a 17 keV neutrino admixing at the 1% level with the electron neutrino. The corresponding upper limit was set at [vert bar][ital U][vert bar][sup 2][lt]0.073% (95% C.L.). A new limit was also obtained for a wider mass range: [vert bar][ital U][vert bar][sup 2][lt]0.15% (95% C.L.) for 10.5 to 25.0 keV neutrinos.

• OSTI ID: 6771219
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 47:11; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
NEUTRINOS
MASS
NICKEL 63
BETA-MINUS DECAY
BETA SPECTRA
FLAVOR MODEL
LIMITING VALUES
BETA DECAY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COMPOSITE MODELS
DECAY
ELEMENTARY PARTICLES
EVEN-ODD NUCLEI
FERMIONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEPTONS
MASSLESS PARTICLES
MATHEMATICAL MODELS
NICKEL ISOTOPES
NUCLEAR DECAY
NUCLEI
PARTICLE MODELS
QUARK MODEL
RADIOISOTOPES
SPECTRA
YEARS LIVING RADIOISOTOPES
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