Parts | Days | Selection | Search | Downloads | Help
T: Teilchenphysik
T 406: Beauty II
T 406.3: Talk
Wednesday, March 12, 2003, 14:30–14:45, SFO9
Search for the decay B → D*+p(p)X
in e+e− Interactions at 91 GeV — •Franz Mandl and Jimmy MacNaughton — Inst. fuer Hochenergiephysik der OAW, Vienna, Austria
A search was made for
the semi-inclusive channel B → D*+p(p)X
in e+e− annihilations into hadrons at LEP (√s = 91 GeV).
Before a measurement, rather than just upper and lower limits, became
available, the branching ratio
Λc → Kpπ
had been determined with the assumption that for
B → D*+p(p)X the branching fraction was negligibly
small, which provided a
motivation to search for this channel.
The present analysis used about 1.4 million hadronic events,
taken by the DELPHI experiment,
more than twice this number of a tuned Monte Carlo sample and about
50,000 events of a special signal Monte Carlo sample containing the above
channel.
A search was made for this channel in the decay chain
D*+ → D0π+ →
(K−π+)π+.
Proton
candidates originating from the B-vertex were isolated by a discriminant
variable analysis based on vertex fit related quantities. The
No-dqtrueNo-dq
proton content was unfolded based on a study of particle identification.
The measurement of the branching ratio
BR(B → D*p(p)X) ∼ (1.88 ± 1.30 ±
0.34)10−2
was converted to an upper limit (95% confidence level):
BR(B → D*p(p)X) < 4.5*10−2.