Scale Factors for Proper Time Uncertainties at CDF
This web page summarizes the blessed results for measurement
of the scale factors for proper time resolution in the CDF detector.
Accurate knowledge of &sigmact is essential for derivation
of a correct lower limit on the Bs oscillation frequency,
and this study has been performed as part of the ongoing CDF effort toward
that measurement. These results were blessed in the B Physics
Meeting of Thursday October 13, 2005.
A complete description can be found in
CDF note 7944.
These results are applied in the
hadronic
and
semileptonic
two-track trigger Bs signal analyses.
The scale factor parameterizations use the following variables:
- Opening angle &Delta R between the momenta of the D meson and the prompt (&pi&pi)&pi
- Vertex isolation i
- Pseudorapidity &eta
- Beamline axis position z
- Vertex fit &chi2
The scale factor for application to the
Bs -> Ds &pi/l signal is of the form:
s = [p0R + p1R &Delta R + p2R &Delta R2]
* [p0i + p1i i + p2i i2]
* [p0&eta + p1&eta &eta + p2&eta &eta2]
* [p0z + p1z z + p2z z2]
* [p0&chi + p1&chi &chi2 + p2&chi (&chi2)2]
with parameter values:
| | &Delta R | i | &eta | z | &chi2 |
| p0 | 1.853 | 1.259 | 0.9790 | 0.99469 | 0.91398 |
| p1 | -0.642 | -0.519 | 0.0046 | -0.00062 | 0.02723 |
| p2 | 0.217 | -0.200 | 0.0928 | 0.00001 | -0.00055 |
The scale factor for application to the
Bs -> Ds 3&pi signal is of the form:
s = [p0i + p1i i + p2i i2]
* [p0z + p1z z + p2z z2]
* [p0&chi + p1&chi &chi2 + p2&chi (&chi2)2]
with parameter values:
| | i | z | &chi2 |
| p0 | 1.442 | 0.99007 | 0.85712 |
| p1 | 0.355 | -0.00016 | 0.02806 |
| p2 | -0.409 | 0.00002 | -0.00071 |
Separate eps versions of all figures:
• Representative proper time fits in the calibration sample:
D&pi
D&pi&pi&pi
• Phase space coverage comparisons for D&pi :
• Phase space coverage comparisons for D&pi&pi&pi :
• Raw scale factor dependences for D&pi :
• 1st - 4th intermediate correction steps for D&pi :
| &Delta R |
iso |
&eta |
z |
&chi2 |
mass |
pT(D&pi) |
pT(&pi) |
| &Delta R |
iso |
&eta |
z |
&chi2 |
mass |
pT(D&pi) |
pT(&pi) |
| &Delta R |
iso |
&eta |
z |
&chi2 |
mass |
pT(D&pi) |
pT(&pi) |
| &Delta R |
iso |
&eta |
z |
&chi2 |
mass |
pT(D&pi) |
pT(&pi) |
• Fully corrected scale factor dependences for D&pi :
• Raw scale factor dependences for D&pi&pi&pi :
• Fully corrected scale factor dependences for D&pi&pi&pi :