| Abstract |
content_type = "text/plain"
user_agent = "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)"
moz = "Mozilla/5.0 "
moz_version = "5"
We study the inclusive electron spectrum of B->X_u e nu decays near the
kinematic limit for B->X_c e nu transitions using a sample of 88 million
Upsilon(4S) decays recorded by the BABAR detector at the PEP II e+e- storage
rings. For the electron momentum interval of 2.0 - 2.6 GeV/c the partial
branching fraction is measured to be DeltaB(B->X_u e nu) = (0.480 +/-
0.029_{stat} +/- 0.053_{syst})x10^{-3}. Combining this result on with
measurements of the inclusive photon spectrum in B->X_s gamma transition we
find |V_ub|=(3.94 +/- 0.25_{exp} +/- 0.37_{f_u} +/- 0.19_{theory})x10^{-3},
where the first error represents the combined statistical and systematic
experimental uncertainty of the partial branching fraction measurement, the
second refers to the uncertainty of the determination of the fraction f_u of
the inclusive electron spectrum that falls within our cuts, and the third error
is due to theoretical uncertainties in the QCD corrections, plus the
uncertainty in the b-quark mass. All results are preliminary.
|
