Measurement of the B 0 s Lifetime Using Semileptonic Decays
Abstract
We report a measurement of the
B
0
s
lifetime in the semileptonic decay channel
B
0
s
→
D
−
s
μ
+
νX
(and its charge conjugate), using approximately 0.4 fb
−1
of data collected with the D0 detector during 2002 -- 2004. We have reconstructed 5176
D
−
s
μ
+
signal events, where the
D
−
s
is identified via the decay
D
−
s
→ϕ
π
−
, followed by
ϕ→
K
+
K
−
. Using these events, we have measured the
B
0
s
lifetime to be
τ(
B
0
s
)=1.398±0.044
(stat
)
+0.028
−0.025
(syst)ps
. This is the most precise measurement of the
B
0
s
lifetime to date.