Data sets with possible 2007 running conditions

Note that both sim files and the corresponding digi files are available (no spill-over due to filled bunch spacing of  2.025 microsec) .

(sim files produced by G.Corti, digi files produced by M.Needham)

Conditions data set location and name nr of events
event type magnetic field velo position Files are located in: /castor/  
 Prim vtx s(x) = s(y) = 280 microns; horizontal crossing angle = 0 mrad
450 GeV/p, collisions off open 30000000.5k.B_OFF.VeloOpen.{sim,digi} 4997
450 GeV/p, collisions off intermediate 30000000.5k.B_OFF.VeloMidway.{sim,digi} 4999
450 GeV/p collisions off close 30000000.5k.B_OFF.VeloClose.{sim,digi} 4998
Prim vtx s(x) = s(y) = 280 microns; horizontal crossing angle = 2.1 mrad
450 GeV/p, collisions on open 30000000.5k.B_ON.VeloOpen.{sim,digi} 4998
450 GeV/p, collisions on close 30000000.5k.B_ON.VeloClose.{sim,digi} 5000 WARNING: ECAL and HCAL were not simulated in these data
Gas in Velo -1m < z < 1m; data sets separated for H, C, O; need to be scaled for gas composition in 2007
beam gas, p-H off open    
beam gas, p-C off open    
beam gas, p-O off open    

The file catalog above is available as Catalog_Pilot_2007.xml

The spread of the beams is different for the Pilot Run (as presented by Ralph Assamann at LHCb Week in Sept. 2006).

As a result the primary vertex distributions are also different with respect to the nominal running conditions.

The settings of the primary vertex s(x) = s(y) = 280 microns is just that of the beam size (value from R.A. is 277mm at b*=10m, it is 70.9 microns at 7TeV at the same b*)

s(z) should also be different than that of nominal running since bunch length at 450 GeV is 11.24 cm instead of 7.55.

In addition the collisions are head on with magnet off while the beams have a +/- 2.1 mrad angle with full field leading to a difference of luminous region in the case of magnet off/on that should also be taken into account.

Alignment samples prepared by Steve Blusk

First data scenarios


  1. Muon group:
  2. Velo:
  3. Luminosity measurement:


Last updated: 03 March 2008