Precision Analysis of the Xe-136 Two-Neutrino beta beta Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21670%2F19%3A00338229" target="_blank" >RIV/68407700:21670/19:00338229 - isvavai.cz</a>
Výsledek na webu
<a href="https://doi.org/10.1103/PhysRevLett.122.192501" target="_blank" >https://doi.org/10.1103/PhysRevLett.122.192501</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1103/PhysRevLett.122.192501" target="_blank" >10.1103/PhysRevLett.122.192501</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Precision Analysis of the Xe-136 Two-Neutrino beta beta Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements
Popis výsledku v původním jazyce
We present a precision analysis of the Xe-136 two-neutrino beta beta electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino beta beta rate allows us to measure the ratio of the leading and subleading 2 nu beta beta nuclear matrix elements (NMEs), xi(2 nu)(31) = -0.26(-0.25)(+0.31). Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the xi(2 nu)(31) range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted xi(2 nu)(31) values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless beta beta decay, xi(2 nu)(31) provides new insights toward reliable neutrinoless beta beta NMEs.
Název v anglickém jazyce
Precision Analysis of the Xe-136 Two-Neutrino beta beta Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements
Popis výsledku anglicky
We present a precision analysis of the Xe-136 two-neutrino beta beta electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino beta beta rate allows us to measure the ratio of the leading and subleading 2 nu beta beta nuclear matrix elements (NMEs), xi(2 nu)(31) = -0.26(-0.25)(+0.31). Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the xi(2 nu)(31) range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted xi(2 nu)(31) values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Because these aspects are also at play in neutrinoless beta beta decay, xi(2 nu)(31) provides new insights toward reliable neutrinoless beta beta NMEs.
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10304 - Nuclear physics
Návaznosti výsledku
Projekt
<a href="/cs/project/EF16_019%2F0000766" target="_blank" >EF16_019/0000766: Inženýrské aplikace fyziky mikrosvěta</a><br>
Návaznosti
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Ostatní
Rok uplatnění
2019
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Physical Review Letters
ISSN
0031-9007
e-ISSN
1079-7114
Svazek periodika
122
Číslo periodika v rámci svazku
19
Stát vydavatele periodika
US - Spojené státy americké
Počet stran výsledku
7
Strana od-do
"192501-1"-"192501-7"
Kód UT WoS článku
000468227800004
EID výsledku v databázi Scopus
2-s2.0-85065833472