Beams Document 539-v3

DocDB Home ]  [ Search ] [ Last 20 Days ] [ List Authors ] [ List Topics ] [ List Events ]

Evaluation of the Beam Width at CDF

Document #:
Beams-doc-539-v3
Document type:
Note
Submitted by:
Jean Slaughter
Updated by:
Jean Slaughter
Document Created:
02 Apr 2003, 16:58
Contents Revised:
03 Apr 2003, 09:38
Metadata Revised:
03 Apr 2003, 09:38
Viewable by:
  • Public document
Modifiable by:
  • Same as Viewable by

Quick Links:
Latest Version

Other Versions:
Beams-doc-539-v2
03 Apr 2003, 09:32
Beams-doc-539-v1
02 Apr 2003, 16:58
Abstract:
Using inclusive jet data, we evaluate the Tevatron beam width at CDF using the
observed vertex distribution from the vxprim module. We take into account
the z-dependence of the beam width and fit it to the functional
form:\\
\[ \sigma_{beam} = \sqrt{\epsilon (\beta^* + (z-z_0)^2/\beta^*)}. \]
We also investigate the
stability of the beam width over the course of a store.
Using select high luminosity runs, we find the following results for the
beam width fit parameters averaged over 6 selected runs:

\[ \epsilon = (1.49\pm0.03)\times 10^{-7} \mbox{ cm}, \beta^* = 37.1\pm1.1 \mbox{ cm},
z_0 = 12.1\pm0.7 \mbox{ cm for } x, \]

\[ \epsilon = (1.49\pm0.02)\times 10^{-7} \mbox{ cm}, \beta^* = 38.0\pm1.0 \mbox{ cm},
z_0 = -8.2\pm0.5 \mbox{ cm for } y. \]

These values are quoted assuming that the Tevatron beam width parameters did not change
over the course of these 6 runs. The uncertainties given are statistical only.

We also find that the average beam widths in $x$ and $y$ are:

\[ \sigma_x^{avg} = 29.6\pm0.4 ~\mu\mbox{m }, \sigma_y^{avg} = 30.4\pm0.4~\mu\mbox{m}. \]

Files in Document:
Topics:
Publication Information:
CDF Note Number: CDF/DOC/SEC_VTX/CDFR/6311
DocDB Home ]  [ Search ] [ Last 20 Days ] [ List Authors ] [ List Topics ] [ List Events ]

DocDB Version 8.8.9, contact Beams Document Database Administrators