Direct neutrino-mass measurement with sub-electronvolt sensitivity
Result description
Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, the absolute neutrino-mass scale remains unknown. Here we report the upper limits on effective electron anti-neutrino mass, m(nu), from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment, m(nu) is probed via a high-precision measurement of the tritium beta-decay spectrum close to its endpoint. This method is independent of any cosmological model and does not rely on assumptions whether the neutrino is a Dirac or Majorana particle. By increasing the source activity and reducing the background with respect to the first physics campaign, we reached a sensitivity on m(nu) of 0.7 eV c(-2) at a 90% confidence level (CL). The best fit to the spectral data yields m(nu)(2) = (0.26 +/- 0.34) eV(2) c(-4), resulting in an upper limit of m(nu) < 0.9 eV c(-2) at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of m(nu) < 0.8 eV c(-2) at 90% CL.
Keywords
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Direct neutrino-mass measurement with sub-electronvolt sensitivity
Original language description
Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, the absolute neutrino-mass scale remains unknown. Here we report the upper limits on effective electron anti-neutrino mass, m(nu), from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment, m(nu) is probed via a high-precision measurement of the tritium beta-decay spectrum close to its endpoint. This method is independent of any cosmological model and does not rely on assumptions whether the neutrino is a Dirac or Majorana particle. By increasing the source activity and reducing the background with respect to the first physics campaign, we reached a sensitivity on m(nu) of 0.7 eV c(-2) at a 90% confidence level (CL). The best fit to the spectral data yields m(nu)(2) = (0.26 +/- 0.34) eV(2) c(-4), resulting in an upper limit of m(nu) < 0.9 eV c(-2) at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of m(nu) < 0.8 eV c(-2) at 90% CL.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10303 - Particles and field physics
Result continuities
Project
LTT19005: Czech Participation at the International Experiment KATRIN
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Nature Physics
ISSN
1745-2473
e-ISSN
1745-2481
Volume of the periodical
18
Issue of the periodical within the volume
2
Country of publishing house
DE - GERMANY
Number of pages
18
Pages from-to
160-166
UT code for WoS article
000755220000019
EID of the result in the Scopus database
2-s2.0-85126257490
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Particles and field physics
Year of implementation
2022