Calibration

MTD Calibration

Calibration Parameters

• Trigger Time Windows -- limit the MTD hits to those that are within a certain window w.r.t. the central TOF clock
• INL -- apply the Integral Non-Linearity electronics calibration (specific to the HPTDC chips) 
• T0 -- align the timing of all the MTD channels
• Slewing -- calibration for amplitude (time-over-threshold) depended timing effects
• Alignment -- correct MTD/TPC alignment, using the residuals between matched TPC track and MTD hit pairs

Procedure

A schematic workflow is shown here, and a detailed description can be found in Calibration Workflow. Details about the calibration procedure can be found here. 

Parameter Storage

• The calibration parameters are stored in the data base. 
• These parameters can also be found here

Calibration Parameters

Run21 (200 GeV O+O)

• T0, slewing and position calibration parameters are taken from Run18 
• Determine timing window for real data: OO 200 GeV
• Global T0 timing: OO 200 GeV
• Check all calibration parameters: OO 200 GeV

Run19 (BES II)

• T0, slewing and position calibration parameters are taken from Run18 
• Determine timing window for real data: AuAu 19.6 GeV
• Check timing window vs. day: AuAu 19.6 GeV
• Global T0 timing: AuAu 19.6 GeV
• Check all calibration parameters: AuAu 19.6 GeV

Run18 (200 GeV Isobar, 27 GeV Au+Au)

• Cosmic ray: T0, slewing and position calibration: slides
• Determine timing window for cosmic ray: slides
  • Change window cut from 3sigma to 3.5 sigma to be conservative, even though this should make very little difference
• Determine timing window for real data: Isobar 200 GeV (083-129), AuAu 27 GeV (part2, also used for part1)
• Check timing window vs. day: Isobar 200 GeV, AuAu 27 GeV (part2, also used for part1)
• Global T0 timing: Isobar 200 GeV (083-129), AuAu 27 GeV part1, part2
• Check all calibration parameters: Isobar 200 GeV (083-129), AuAu 27 GeV part1, part2

Run17 (500 GeV p+p, 54 GeV Au+Au)

• Determine timing window for cosmic ray: slides
• Determine timing window for real data: pp 500 GeV, AuAu 54 GeV
• Check timing window vs. day: pp 500 GeV
• Global T0 timing: pp 500 GeV, AuAu 54 GeV
• Check all calibration parameters: pp 500 GeV, AuAu 54 GeV

Run16 (200 GeV Au+Au, 20-200 GeV d+Au)

• Determine timing window for cosmic ray: slides
• Determine timing window for real data: slides (the same timing window cuts are used for all data sets)
• Check timing window vs. day: slides
• Global T0 timing: AuAu 200 GeV, dAu 200 GeV, dAu 20-62 GeV
• Check timing window cuts: dAu 200 GeV, dAu 20-62 GeV
• Check all calibration parameters: AuAu 200 GeV, dAu 200 GeV, dAu 20-62 GeV

Run15 (200 GeV p+p, p+Au)

• Determine timing window for cosmic ray: slides
• Determine timing window real data: 046-117, 125-158, 161-169
• Global T0 timing: slides
• Check timing window cuts: slides

Run14 (200 GeV Au+Au)

• Determine timing window for cosmic ray data: slides
• Determine timing window for real data: slides
• Compare mean and sigma of dT distributions between data and cosmic ray: mean, sigma

Run13 (510 GeV p+p)

• Determine timing window for cosmic ray: slides
• Determine timing window for real data: 130-149, 151-161
  
• Check timing window vs. day: slides
• Compare mean and sigma of dT distributions between data and cosmic ray: mean, sigma