Using 20.3 fb-1 of e+e- collision data collected at a center-of-mass energy of Ec.m.=3.773 GeV with the BESIII detector operating at the BEPCII collider, we determine the branching fraction of the leptonic decay D+→μ+νμ to be (4.034±0.080stat±0.040syst)×10-4. Interpreting our measurement with knowledge of the Fermi coupling constant GF, the masses of the D+ and μ+ as well as the lifetime of the D+, we determine fD+|Vcd|=(48.02±0.48stat±0.24syst±0.12input±0.15EM) MeV after taking into account necessary radiative corrections. This result is a factor of 2.3 more precise than the previous best measurement. Using the value of the magnitude of the c→d Cabibbo-Kobayashi-Maskawa matrix element |Vcd| given by the global standard model fit, we obtain the D+ decay constant fD+=(213.5±2.1stat±1.1syst±0.8input±0.7EM) MeV. Alternatively, using the value of fD+ from a precise lattice quantum chromodynamics calculation, we extract |Vcd|=0.2265±0.0023stat±0.0011syst±0.0009input±0.0007EM.

Precision Measurement of the Branching Fraction of D+→μ+νμ

Amoroso, A.;Bianchi, F.;Bortone, A.;Destefanis, M.;De Mori, F.;Greco, M.;Maggiora, M.;Marcello, S.;Sosio, S.;Spataro, S.;
2025-01-01

Abstract

Using 20.3 fb-1 of e+e- collision data collected at a center-of-mass energy of Ec.m.=3.773 GeV with the BESIII detector operating at the BEPCII collider, we determine the branching fraction of the leptonic decay D+→μ+νμ to be (4.034±0.080stat±0.040syst)×10-4. Interpreting our measurement with knowledge of the Fermi coupling constant GF, the masses of the D+ and μ+ as well as the lifetime of the D+, we determine fD+|Vcd|=(48.02±0.48stat±0.24syst±0.12input±0.15EM) MeV after taking into account necessary radiative corrections. This result is a factor of 2.3 more precise than the previous best measurement. Using the value of the magnitude of the c→d Cabibbo-Kobayashi-Maskawa matrix element |Vcd| given by the global standard model fit, we obtain the D+ decay constant fD+=(213.5±2.1stat±1.1syst±0.8input±0.7EM) MeV. Alternatively, using the value of fD+ from a precise lattice quantum chromodynamics calculation, we extract |Vcd|=0.2265±0.0023stat±0.0011syst±0.0009input±0.0007EM.
2025
135
6
1
10
Ablikim, M.; Achasov, M. N.; Adlarson, P.; Afedulidis, O.; Ai, X. C.; Aliberti, R.; Amoroso, A.; An, Q.; Bai, Y.; Bakina, O.; Balossino, I.; Ban, Y.; ...espandi
File in questo prodotto:
File Dimensione Formato  
gb8v-4rnh.pdf

Accesso aperto

Tipo di file: PDF EDITORIALE
Dimensione 428.35 kB
Formato Adobe PDF
428.35 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/2117971
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact