It is shown that the kinematical difference in the decays B- → D0ℓν̃ and B0 → D+ℓν̃ due to the isotopic mass splittings of the B and D mesons is compensated in the total decay rate by an appropriate difference in the lepton spectra. Thus there is no effect on the total decay rates in the linear order in the isotopic mass splittings, as required by the general consideration based on the operator product expansion. Although phenomenologically the isotopic difference in the spectra amounts to at most about 1%, in the theoretical aspect this effect can be viewed as an additional illustration of how the general OPE results emerge from the properties of exclusive channels.
|Original language||English (US)|
|Number of pages||5|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Aug 13 1998|
Bibliographical noteFunding Information:
I am thankful to Arkady Vainshtein and Yuichi Kubota for enlightening discussions of the theoretical aspects and experimental possibilities. This work is supported in part by the DOE grant DE-FG02-94ER40823.