Short Distance Analysis of $\bar{B}->D^{(\ast )0}e+e-$ and $\bar{B}->J/psie+e-$

Abstract

Over a large fraction of phase space a combination of an operator product and heavy quark expansions effectively turn the decay $\bar{B}->D^{(\ast )0}e+e-$ into a ``short distance'' process, i.e., one in which the weak and electromagnetic interactions occur through single local operators. These processes have an underlying W-exchange quark diagram topology and are therefore Cabibbo allowed but suppressed by combinatoric factors and short distance QCD corrections. Our technique allows a clearer exploration of these effects. For the decay ${\bar{B}}_{d,s}->J/psi({\eta }_c)e+e-$ one must use a non-relativistic (NRQCD) expansion, in addition to an operator product expansion and a heavy quark effective theory expansion. We estimate the decay rates for ${\bar{B}}_{d,s}->J/psie+e-$, ${\bar{B}}_{d,s}->et{a}_{c}e+e-$, ${\bar{B}}_{d,s}->D^{\ast 0}e+e-$ and ${\bar{B}}_{d,s}->D^{0}e+e-$.

Comments: 13 pages, 11 figures, published version