https://doi.org/10.1140/epjc/s10052-020-7758-4
Regular Article - Theoretical Physics
The 
semileptonic and radiative decays within the light-cone sum rules
1
Department of Physics and Institute of Particle Physics, Guizhou Minzu University, Guiyang, 550025, People’s Republic of China
2
State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190, People’s Republic of China
3
Department of Physics, Chongqing University, Chongqing, 401331, People’s Republic of China
* e-mail: wuxg@cqu.edu.cn
Received:
2
December
2019
Accepted:
19
February
2020
Published online:
3
March
2020
The measured branching ratio of the D meson semileptonic decay 
, which is based on the 
CLEO data taken at the peak of 
resonance, disagrees with the traditional SVZ sum rules analysis by about three times. In the paper, we show that this discrepancy can be eliminated by applying the QCD light-cone sum rules (LCSR) approach to calculate the transition form factors 
and 
. After extrapolating the LCSR predictions of these TFFs to whole 
-region, we obtain 
. Using the CKM matrix element and the 
lifetime from the Particle Data Group, we obtain 
and 
, which agree with the CLEO measurements within errors. We also calculate the branching ratios of the two D meson radiative processes and obtain 
and 
, which also agree with the Belle measurements within errors. Thus we think the LCSR approach is applicable for dealing with the D meson decays.
© The Author(s), 2020
