Determination of |Vcb| using B RIGHTWARDS ARROW Dlνl decays at Belle II

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10511005" target="_blank" >RIV/00216208:11320/25:10511005 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=X14Xe~.jPI" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=X14Xe~.jPI</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1103/vs8k-259v" target="_blank" >10.1103/vs8k-259v</a>

Result language
angličtina
Original language name
Determination of |Vcb| using B RIGHTWARDS ARROW Dlνl decays at Belle II
Original language description
We present a determination of the Cabibbo-Kobayashi-Maskawa matrix element |V-cb| from the decay B -> Dl nu(l) using a 365 fb(-1) e(+)e(-) -> Upsilon(4S) -> B (B) over bar data sample recorded by the Belle II experiment at the SuperKEKB collider. The semileptonic decay of one B meson is reconstructed in the modes B-0 -> D-(-> K+pi(-)pi(-))l(+)nu(l) and B+ -> (D) over bar (0)(-> K+ pi(-))l(+)nu(l), where l denotes either an electron or a muon. Charge conjugation is implied. The second B meson in the Upsilon(4S) event is not reconstructed explicitly. Using an inclusive reconstruction of the unobserved neutrino momentum, we determine the recoil variable w = v(B) . v(D), where v(B) and v(D) are the four-velocities of the B and D mesons. We measure the total decay branching fractions to be B(B-0 -> D(-)l(+)nu(l)) = (2.06 +/- 0.05(stat) +/- 0.10(sys))% and B(B+ -> (D) over bar (0)l(+)nu(l)) = (2.31 +/- 0.04(stat) +/- 0.09(sys))%. We probe lepton flavor universality by measuring B(B -> De nu(e))/B(B -> D mu nu(mu)) = 1.020 +/- 0.020(stat) +/- 0.022(sys). Fitting the partial decay branching fraction as a function of w and using the average of lattice QCD calculations of the B -> D form factor, we obtain |V-cb| = (39.2 +/- 0.4(stat) +/- 0.6(sys) +/- 0.5(th)) x 10(-3).
Czech name
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Czech description
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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

Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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