Ponente
Dr.
Arantza Oyanguren
(IFIC- Valencia)
Descripción
The charm semileptonic decay $D \to \pi e \nu$ has been measured by several experiments. Conversely to other semileptonic decays, this channel presents the interest that contributions from the two first poles can be predicted. We have computed accurately in LQCD the ratio of decay constants $f_{D^\ast}/f_D$ making the evaluation of the $D^\ast$-pole contribution quite accurate. Measurements of the above charm semileptonic decay have been analyzed using a model with $3$ poles, the last one being effective. It is found that data agree with the superconvergence condition according to which the sum of the residues at the various poles amounts to zero. This analysis is extended to $B\to \pi e \nu$ decays for which we compute the ratio $f_{B^\ast}/f_B$. We find that both decays verify the superconvergence condition which also assures validity of the heavy quark scaling law in the large recoil limit. We then verify that the value of $V_{ub}$ we extract from a comparison with the experimental data is consistent with those previously found from the exclusive semileptonic decays.
Autores primarios
Prof.
Alain Le - Yaouanc
(LPT Orsay)
Dr.
Arantza Oyanguren
(IFIC- Valencia)
Prof.
Damir Becirevic
(LPT Orsay)
Dr.
Francesco Sanfilippo
(University of Southampton)
Prof.
Patrick Roudeau
(LAL Orsay)
