Measurement of the Bs - Bs Oscillation Frequency
We report a measurement of the Bs - Bs oscillations and a determination of |Vtd|/|Vts| using the CDF Detector operating at the Fermilab Tevatron. This result is derived from 1 fb-1 of pp collisions at 1.96TeV. We use semileptonic and hadronic Bs meson decays and observe a signature consistent with Bs - Bs oscillations. The probability that the data could randomly fluctuate to mimic such a signature is 0.2%. The results are as follows:
|
Δms |
= 17.31 |
+ 0.33
- 0.18 |
(stat) |
± 0.07(sys) |
|
|
|Vtd|
|Vts| |
= 0.208 |
+0.001
- 0.002 |
(stat +sys) |
+0.008
- 0.006 |
(theo) |
|
This result has been published in PRL: PRL 97, 062003 (2006).
This result supersedes limits set using 365 pb-1 in hadronic and semileptonic decays.
Figures
Below are eps and gif versions of the most interesting figures.
- Hadronic decay modes
- Figure 1: gif - eps : Mass Projection Bs &rarr Ds &pi(&pi&pi)
- Figure 2: gif - eps : Mass Projection Bs &rarr Ds &pi with Ds &rarr &phi&pi
- Figure 3: gif - eps : ct Projection Bs &rarr Ds &pi(&pi&pi)
- Semileptonic decay modes
- Figure 4: gif - eps : Ds Mass from Bs &rarr Ds l &nu X decays
- Figure 5: gif - eps : l Ds Mass from Bs &rarr Ds l &nu X decays
- Figure 6: gif - eps : ct Projection Bs &rarr Ds l &nu X decays
- ct resolution
- Figure 7: gif - eps : Hadronic decay modes ct resolution
- Figure 8: gif - eps : Semileptonic decay modes ct resolution
- Figure 9: gif - eps : Semileptonic decay modes ct resolution vs. K factor
- Figure 10: gif - eps : Semileptonic decay modes K factor
- Figure 11: gif - eps : ct resolution calibration sample
- Amplitude Scans and Likelihood Plots
- Figure 12: gif - eps : Combined amplitude scan
- Figure 13: gif - eps : Combined amplitude scan(statistical errors only)
- Figure 14: gif - eps : Plot of signal vs. fluctuation toys
- Figure 15: gif - eps : Wide range likelihood plot
- Figure 16: gif - eps : Narrow range likelihood plot
- Figure 17: gif - eps : PRL amplitude scan and likelihood
Experimental Status
Below is a comparison of this result to relevant experimental work:
D0 PRL 97, 021802 (2006): 17 < &Deltams < 21 ps-1 at 90%CL with most probable value 19ps-1
and 5% probability of fluctuation
Unitary triangle fits: CKMFitter and UTFit (fits with new CDF result available from UTFit and CKMFitter)
