摘要
In this study,D→P(π,K) helicity form factors(HFFs) are investigated by applying the QCD light-cone sum rule(LCSR) approach.The calculation accuracy is up to the next-to-leading order(NLO) gluon radiation correction of twist-(2,3) distribution amplitude.The resultant HFFs at a large recoil point are Pt,0π(0)=0.688-0.024+0.020 and Pt,0K(O)=0.780-0.029+0.024,in which the contributions from the three particles of the leading order(LO) are so small that they can be safely neglected.The maximal contribution of the NLO gluon radiation correction for Pt,0r,K(0) is less than3%.After extrapolating the LCSR predictions for these HFFs to the whole q2-region,we obtain the decay widths for semileptonic decay processes D→Plvl,which are consistent with the BES-Ⅲ collaboration predictions within error limits.After considering the D+/D0-meson lifetime,we give the branching fractions of D→Plvl with l=e,μ;our predictions also agree with the BES-Ⅲ collaboration results within error limits,especially for the D→πlvl decay process.Finally,we present the forward-backward asymmetry AFBl(q2) and lepton convexity parameter CFl(q2),and further calculate the mean value of these two observations,<AFBl> and {CFl),which may provide a way to test those HFFs in future experiments.
作者
付海冰
程伟
周瑞雨
曾龙
Hai-Bing Fu;Wei Cheng;Rui-Yu Zhou;Long Zeng(Institute of Particle Physics&Department of Physics,Guizhou Minzu University,Guiyang 550025,China;CAS Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190,China;Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100190,China;Department of Physics,Chongqing University,Chongqing 401331,China)
基金
Supported in part by the National Science Foundation of China(11765007)
the National Natural Science Foundation of China(11947302)
the Project of Guizhou Provincial Department of Science and Technology(KY[2017]1089,No.KY[2019]1171)
the China Postdoctoral Science Foundation(2019TQ0329)。