Run 9 Vernier Scan BBC Cross Section: Initial Look
First look at the absolute BBC cross section obtained via vernier scans taken during Run 9 ...
Figure 1: Vernier scan results obtained from Angelika Drees. The top panel shows the BBC cross section extracted from the various scans. The bottom panel shows the BBC cross sections as a function of luminosity.
The first six points were taken during the normal 200 GeV data taking period. The associated fills are 10642, 10652, 10746, 10777, 10866, and 10968. The corresponding days are: 112, 114, 134, 142, 156, and 173. The data in my analyses start on day 120 and end on day 180, the RFF / FF difference happened around day 148.
The last three points were taken during the pp2pp running during fills 11020, 11031, and 11032 corresponding to days 182 and 184.
The last point during the nominal running period (fill 10968) was taken during a period when the BBC rate seems to have dropped anonymously. The point on the plot was scaled up by the amount the BBC rate dropped.
Figure 2: Plot of the RICH scalar info for the BBCX (red) VPDEW (blue) and ZDC and (green) from fill 10968.
Figure 3: Top panel shows the BBC cross (open squares) along with the ZDC cross section (blue circles) where the ZDC cross section has been scaled up by a factor of 100. The bottom panel shows the dependence of the BBC cross section on the bunch length (or an approximation of the bunch length): bunch length = sqrt(0.5*(yellBunchLength**2 + blueBunchLength**2)).
Figure 1: Vernier scan results obtained from Angelika Drees. The top panel shows the BBC cross section extracted from the various scans. The bottom panel shows the BBC cross sections as a function of luminosity.
The first six points were taken during the normal 200 GeV data taking period. The associated fills are 10642, 10652, 10746, 10777, 10866, and 10968. The corresponding days are: 112, 114, 134, 142, 156, and 173. The data in my analyses start on day 120 and end on day 180, the RFF / FF difference happened around day 148.
The last three points were taken during the pp2pp running during fills 11020, 11031, and 11032 corresponding to days 182 and 184.
The last point during the nominal running period (fill 10968) was taken during a period when the BBC rate seems to have dropped anonymously. The point on the plot was scaled up by the amount the BBC rate dropped.
Figure 2: Plot of the RICH scalar info for the BBCX (red) VPDEW (blue) and ZDC and (green) from fill 10968.
Figure 3: Top panel shows the BBC cross (open squares) along with the ZDC cross section (blue circles) where the ZDC cross section has been scaled up by a factor of 100. The bottom panel shows the dependence of the BBC cross section on the bunch length (or an approximation of the bunch length): bunch length = sqrt(0.5*(yellBunchLength**2 + blueBunchLength**2)).
Groups:
- pagebs's blog
- Login or register to post comments