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2015 pp vertex properties

Updated on Thu, 2015-11-19 17:56. Originally created by yipkin on 2015-11-19 17:42.
Since Rafal and Lukasz asked me, I have helped look for the answers about the 2015 vertex properties.    I just wrote them down here:
  1. Nov. 18, 2015: Angelika told me (from C-AD resources):
    • " ... looked at two stores with vernier scans. RMS width was between 0.270 and 0.290 mm (round beams, i.e. it's the same in x and y). this is NOT beam size but OVERLAP area of the two beams (since you asked for the vertex). "

    • " ...keep in mind that length as well as transverse sizes are growing throughout a store (by about 25% during a store in z, and this can be much larger in the transverse planes, i.e. up to 60% or more).

    • For the longitudinal (z) direction, "In store 18943, at the time of the vernier scan (about 4 h into the store), the rms length of the overlap was about 5 ns. "
       
  2. Nov. 19, 2015: Gene Van Buren told me about the x/z and y/z vertex slopes (using STAR detectors TPC etc.):

    "Here are the database timestamps, x-z plane intercept and slope, y-z plane intercept and slope, and then errors on those 4 quantities. Units (if any) are [cm].

    This calibration was done without the HFT and there were some mysteries. I've yet to document it though. Still on my to-do list...

    Hope that helps,
    -Gene"

    timestamp	            x0	           dx/dz	     y0	           dy/dz	  err_x0	 err_dx/dz	 err_y0	        err_dy/dz 

2015-04-04 00:27:20	0.01148700	-0.00060000	-0.26245499	0.00030000	0.00028200	0.00020000	0.00029200	0.00020000 
2015-03-18 11:02:24	0.00639500	-0.00060000	-0.25920299	0.00030000	0.00026500	0.00020000	0.00027000	0.00020000 
2015-03-14 10:07:10	-0.00375900	-0.00060000	-0.29076600	0.00030000	0.00141300	0.00020000	0.00242800	0.00020000 
2015-03-06 00:20:00	-0.00978100	-0.00060000	-0.34444100	0.00030000	0.00045400	0.00020000	0.00038700	0.00020000 
2015-02-16 21:40:56	-0.02643500	-0.00060000	-0.32899201	0.00030000	0.00038500	0.00020000	0.00024200	0.00020000 
2015-02-10 23:20:03	0.01605100	-0.00060000	-0.28795600	0.00030000	0.00119900	0.00020000	0.00089500	0.00020000
    • So, the dx/dz and dy/dz are  -0.00060000  and 0.00030000 respectively.
       


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