Semileptonic D(s) -meson decays in the light of recent data

Abstract

Inspired by recent improved measurements of charm semileptonic decays at BESIII, we study a large set of D(D s )-meson semileptonic decays where the hadron in the final state is one of D 0 , ρ, ω, η (′) in the case of D + decays, and D 0 , φ, K 0 , K * (892) 0 , η (′) in the case of D + s decays. The required hadronic form factors are computed in the full kinematical range of momentum transfer by employing the covariant confined quark model developed by us. A detailed comparison of the form factors with those from other approaches is provided. We calculate the decay branching fractions and their ratios, which show good agreement with available experimental data. We also give predictions for the forward-backward asymmetry and the longitudinal and transverse polarizations of the charged lepton in the final state.

Observation of the semimuonic decay D+→ωμ+νμ

“…Table II shows the comparison of our BF to various theoretical calculations of D þ → ωμ þ ν μ decay. Our BF is consistent with the predicted values based on the LFQM, CCQM, and LCSR methods [14,[16][17][18], but differs from those based on the χUA [15] and RQM [19] methods by 2.5σ and 1.5σ, respectively. Combining the B D þ →ωμ þ ν μ measured in this work with the world average B PDG D þ →ωe þ ν e ¼ ð16.9 AE 1.1Þ × 10 −4 [12,32,38], we obtain the BF ratio to be B D þ →ωμ þ ν μ =B PDG D þ →ωe þ ν e ¼ 1.05 AE 0.14.…”

“…It agrees with the standard model predictions (0.93-0.99) [14][15][16][17]19] within uncertainties, and implies no violation of e-μ LFU found with current statistics.…”

“…Although this decay was theoretically predicted before 1990 [13], it has never been experimentally confirmed yet to date. Since 2015, different theoretical approaches, e.g., light-front quark model (LFQM) [14], recalled chiral unitary approach (χUA) [15], covariant confined quark model (CCQM) [16], light-cone QCD sum rules (LCSR) [17,18], and relativistic quark model (RQM) [19], were adopted to investigate D þ → ωμ þ ν μ . The predicted BFs range between ð1.78-2.46Þ × 10 −3 [14][15][16][17][18][19], corresponding to the BF ratios B D þ →ωμ þ ν μ = B D þ →ωe þ ν e of (0.93-0.99).…”

“…Comparison of the BFs between D þ → ωe þ ν e and D þ → ωμ þ ν μ .CCQM[14] χUA[15] LFQM[16] LCSR[17] LCSR[18] RQM[19] MeasurementB D þ →ωμ þ ν μ (×10 AE 1.1 [12] B D þ →ωμ þ ν μ =B PDG D þ →ωe þ ν e…”

Measurement of the Dynamics of the Decays Ds+→η(′)eAblikim1, Ачасов2, Ahmed3 et al. 2019Phys. Rev. Lett.322220View full textAdd to dashboardCite

“…Furthermore, by taking jV cs j from a standard model fit (CKMFITTER [22]) as input, we determine the FF at zero momentum transfer f η ð0Þ þ ð0Þ for the first time. The obtained FFs provide important data to distinguish various theoretical calculations [6][7][8][45][46][47][48]. Alternatively, we also determine jV cs j with D þ s → η ð0Þ e þ ν e decays for the first time, by taking values for f η ð0Þ þ ð0Þ calculated in theory.…”