For which of these topics can we expect an update by LP05?
Vera
-----Original Message-----
From: [log in to unmask] [mailto:[log in to unmask]] On Behalf Of Concezio Bozzi
Sent: Thursday, April 07, 2005 8:39 AM
To: vub-recoil
Cc: Simonetto, Franco; [log in to unmask]; [log in to unmask]
Subject: Abstract for LP2005
Dear all,
I have prepared an abstract for LP2005, which should be sent to the PAC early next week. Could you please let me know if you have any corrections/suggestions/comments/etc.
Thanks, Concezio.
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Measurements of charmless semileptonic B decays and determination of
|Vub|
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Charmless semileptonic decays, $B \to X_u \ell\nu$, are studied on a sample of 215 million BB decays recorded with the BABAR detector, in events where the decay of the second B meson is fully reconstructed.
Inclusive charmless decays are selected in kinematic regions where the dominant background from semileptonic B decays to charm is reduced by requirements on the hadronic mass Mx, the electron energy El, and the momentum transfer q^2. Signal efficiency and background are estimated from Monte Carlo simulation and data control samples and used to measure partial branching fractions for $B\to X_{u} e \nu$. The CKM matrix element $|V_{ub}|$ is determined by using theoretical calculations.
Theoretical uncertainties in this extrapolation are studied in detail, and reduced by using the inclusive photon spectrum from $b \to s \gamma$ transitions and the moments of the lepton energy and hadronic invariant mass in semileptonic B decays to charm.
In addition, we have isolated various exclusive charmless decay modes.
>From the resulting small sample of exclusive decays, such as $B \to \pi
(\rho, \omega, \eta) \ell \nu$ we have obtained preliminary exclusive branching fraction measurements.
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