1 / 8

Bunch-by-bunch (relative) polarization measurements using inner annuli of STAR BBC

Bunch-by-bunch (relative) polarization measurements using inner annuli of STAR BBC. Andrew Gordon April 4, 2008. Inner tiles of BBC accumulated every clock cycle. {. Hank’s Scaler Boards. }. Discriminated phototube outputs. 24-bit word is histogrammed every clock cycle. {.

lixue
Download Presentation

Bunch-by-bunch (relative) polarization measurements using inner annuli of STAR BBC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bunch-by-bunch (relative) polarization measurements using inner annuli of STAR BBC Andrew Gordon April 4, 2008

  2. Inner tiles of BBC accumulated every clock cycle { Hank’s Scaler Boards } Discriminated phototube outputs 24-bit word is histogrammed every clock cycle { East-West Coincidence } Bunch Crossing (7-bits)

  3. Require Keeps ~5% of all bunch crossings. East-West coincidence (Backgrounds from single beam accidentals less than ~1% of sample after this requirement.) Top and bottom of inner tiles clean to reduce dilution of asymmetry Keeps 20% of the 5%=1% of all crossings pass both requirements. Use tiles 5+6 for Left, tiles 2+3 for Right Typical numbers on the order of ~3M events per bunch per hour ~3.5 s (statistical) measurement of polarization per bunch per hour

  4. Width=1.220.15 Yellow (east BBC) sig Width=1.050.12 Blue (west BBC) sig (|Pbx|-<|Pbx|>) Sigbx= sbx Statistical uncertainties only

  5. Width=1.120.14 Yellow sig Width=0.910.09 Blue sig (|Pbx|-<|Pbx|>) Sigbx= sbx Statistical uncertainties only

  6. Width=1.160.13 Yellow sig Width=0.790.08 Blue sig (|Pbx|-<|Pbx|>) Sigbx= sbx Statistical uncertainties only

  7. Width=1.060.16 Yellow sig Width=0.840.07 Blue sig (|Pbx|-<|Pbx|>) Sigbx= sbx Statistical uncertainties only

  8. Conclusions We can see the relative polarization per bunch at a rate of several measurements per fill. Polarization is largely consistent across bunches. To do Measurement requires calibration to determine polarization at STAR. Can be extended to all Run 8 fills.

More Related