Statut  Confirmé 
Série  IPNX 
Domaines  hepph 
Date  Jeudi 8 Novembre 2018 
Heure  11:00 
Institut  CPHT 
Salle  Salle de Conferences Louis Michel, bat. 6, CPHT, Ecole polytechnique 
Nom de l'orateur  Pham 
Prenom de l'orateur  Tri Nang 
Addresse email de l'orateur  
Institution de l'orateur  CPHT, Ecole polytechnique 
Titre  Heavy to Light Meson Semileptonic Decays Form Factors 
Résumé  Like the twophoton and twogluon decays of the $P$wave $\chi_{c0,2}$ and $\chi_{b0,2}$ state for which the Born term produces a very simple decays amplitude in terms of an effective Lagrangian with twoquark local operator, the Born term for the processes $c\bar{d}\to(\pi,K)\ell\nu $ and $b \bar{d}\to(\pi, K)\ell\nu $, could also produce the $D$ and $B$ meson semileptonic decays with the light meson $\pi, K$ in the final state. In this approach to heavylight meson form factors with the $\pi, K$ meson treated as Goldstone boson, a simple expression is found for the decays form factors, given as~: $f_{+}(0)/(1q^{2}/(m_{H}^{2}+m_{\pi}^{2}))$, with $H=D,B$ for $D,B\to\pi$ form factors, and $f_{+}(0)/(1q^{2}/(m_{H}^{2}+ m_{K}^{2}))$ for $B, D\to K$ form factor. In this talk, I would like to present a recent work showing that this expression for the form factors could describe rather well the $q^{2}$behaviour observed in the BaBar, Belle and BESSIII measurements and lattice simulation. In particular, the $D\to K$ form factors are in good agreement with the measured values in the whole range of $q^{2}$ showing evidence for $SU(3)$ breaking with the presence of $m_{K}^{2}$ term in the quark propagator, but some corrections to the Born term are needed at large $q^{2}$ for $D, B\to\pi$ form factors. 
Numéro de preprint arXiv  
Commentaires  
Fichiers attachés 
Pour obtenir l' affiche de ce séminaire : [ Postscript  PDF ]

[ English version ] 