Test of light-lepton universality in τ decays with the Belle II experiment
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10494174" target="_blank" >RIV/00216208:11320/24:10494174 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=tg2mV51Xbs" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=tg2mV51Xbs</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/JHEP08(2024)205" target="_blank" >10.1007/JHEP08(2024)205</a>
Alternative languages
Result language
angličtina
Original language name
Test of light-lepton universality in τ decays with the Belle II experiment
Original language description
We present a measurement of the ratio Rμ = B(τ- RIGHTWARDS ARROW μ--νμντ )/B(τ- RIGHTWARDS ARROW e--νeντ )of branching fractions B of the τ lepton decaying to muons or electrons using data collectedwith the Belle II detector at the SuperKEKB e+e- collider. The sample has an integratedluminosity of 362 +- 2 fb-1 at a centre-of-mass energy of 10.58 GeV. Using an optimised eventselection, a binned maximum likelihood fit is performed using the momentum spectra ofthe electron and muon candidates. The result, Rμ = 0.9675 +- 0.0007 +- 0.0036, where thefirst uncertainty is statistical and the second is systematic, is the most precise to date. Itprovides a stringent test of the light-lepton universality, translating to a ratio of the couplingsof the muon and electron to the W boson in τ decays of 0.9974 +- 0.0019, in agreement withthe standard model expectation of unity.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10300 - Physical sciences
Result continuities
Project
<a href="/en/project/GA22-18469S" target="_blank" >GA22-18469S: Studies of the Beyond Standard Model phenomena in the flavor sector with the Belle II Experiment</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2024
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of High Energy Physics
ISSN
1029-8479
e-ISSN
1029-8479
Volume of the periodical
2024
Issue of the periodical within the volume
8
Country of publishing house
DE - GERMANY
Number of pages
22
Pages from-to
205
UT code for WoS article
001318710300001
EID of the result in the Scopus database
2-s2.0-85202947583