Measurement of the Bs→ K+K-
lifetime and extraction of ΔΓCPCP

This webpage collects the links to the CDF public note and the relevant supporting plots
of the Bs→K+K- lifetime measurement.
The results have been blessed at the CDF B-Physics meeting on Thursday Jan 26, 2006.


We present the first measurement of the lifetimes of the Bs and Bd mesons in two-body charmless decays:
Bs→ K+ K-, Bd→ K+ pi- and Bd→ pi+ pi-, produced in p-pbar collisions at sqrt{s} = 1.96 TeV.
We use a sample of B→hh decays collected by the CDF detector, corresponding to about 360 pb-1 of data,
collected between February 2002 and August 2004.

We measure
τ(Bd) = 1.51 ± 0.08 (stat) ± 0.02 (syst) ps
τ(Bs→ K+ K-) = 1.53 ± 0.18 (stat) ± 0.02 (syst) ps

Using the latest HFAG average of the Bs lifetime in flavor specific decays:
τ (Bs FS)= 1.454 ± 0.040 ps,
and using our determination of the BsKK lifetime, we determine:
ΔΓCPCP(Bs→ K+K-) = -0.08 ± 0.23 ± 0.03


A complete description of the analysis is available here: ps.


Below the eps versions of all figures available for download.