Evidence for the leptonic decay D→μν

Abstract

Purely leptonic decays of the charged D meson have been studied using the reaction e q e y ™ D )q D y at a center of mass energy of 4.03 GeV. A search was performed for D ™ mn recoiling against a D 0 or D q which had been m y0.05y0.02 D y150y40MeV.

Precision measurement ofB(D+→μ+ν)and the pseudoscalar decay constantfEisenstein1, Karliner2, Mehrabyan3 et al. 2008Phys. Rev. D1068600View full textAdd to dashboardCite

“…Our new values are consistent with our previous measurement [23], as well as the upper limit set by Mark III [33], and the results based on reported yields of 1 and 2.7 events from BES I and II [34], respectively. We also determine f Ds /f D + = 1.326 ± 0.075, using the world average value of absolute measurements for D + s → ℓ + ν as compiled by Rosner and Stone [5], where we include the radiative correction also on the D + s rate.…”

Precision measurements ofB(D+→μ+νμAblikim1, Ачасов2, Ai3 et al. 2014Phys. Rev. D544230View full textAdd to dashboardCite

“…This measured branching fraction is consistent within errors with those measured at BES-I [12], BES-II [13], and CLEO-c [10], but with the best precision. The systematic uncertainty in the D þ → μ þ ν μ branching fraction determination includes seven contributions: (1) the uncertainty in the number of D − tags (0.5%), which contain the uncertainty in the fit to the M BC distribution (0.5%) and the difference in the fake π 0 rates between the data and the Monte Carlo events (0.1%); (2) the uncertainty in μ tracking/identification (0.1%=0.8%) determined by comparing the μ tracking/identification efficiencies for data and Monte Carlo events, where the μ AE samples are from the copious e þ e − → γμ þ μ − process; (3) the uncertainty in the E γ max selection requirement (0.1%) determined by comparing doubly tagged DD hadronic decay events in the data and Monte Carlo; (4) the uncertainty associated with the choice of the M 2 miss signal window (0.5%) determined from changes in the measured branching fractions using different 2 (color online).…”

Decay Constants of Heavy–light Mesons in the Relativistic Quark Model

“…There exists also the first experimental value for f D + = 300 +180+80 −150−40 MeV, but based on only one D + → µ + ν µ event 10 and thus with very large errors. We see from Table 2 that there is good (within error bars) agreement between all presented theoretical predictions as well as with available experimental data.…”