TP Calorimetry and particle ID

Jaewon Park

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Calorimetry

We assumed that (dE/dx)min is constant for different particles.

In previous study: Hcal calibration constant is acquired from proton beam

study. Ecal calibration constant is acquired from electron beam

study.

In TP(tracker+DS-Ecal) study, it shows we can’t use same calibration constant for proton and electron.

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Proton -- Ecal calibration constant

Old study showed Ecal calibration constant 2.5 is better than 1.75

Mean of (recoE-trueE)/trueE become constant for theta, Vz depedence

Value 1.75 is from dE/dx weighting.

Calorimetry constant 2.5 overestimates proton’s energy.K_ecal=1.5 K_ecal=1.75

K_ecal=2.5

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TP Detector – Proton

Ecal calib. constatant = 2.5

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Nu_e electron events (k_ecal=1.5)

It underestimates electron’s energy.

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Nu_e electron energy (k_ecal=2.5)

2.5 shows better energy reconstuction.

It’s consistent with previous Ecal study with electron beam.

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Nu_e electron energy (k_ecal=2.5)

When electron track is reconstructed.

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dE/dx

From graph, dE/dx (electron) is higher thatn dE/dx (proton) around 2-5GeV

scintscintmin

scintscintminiron

leadminscint

losstotalloss )(

)()(

L

LLEE

dxdE

dxdE

dxdE

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dE/dx of reconstructed tracks

Particle beam is shot perpendicular to scintillator planes in semi-infinite tracker.

To localize only beginning of track, it process dE variable until: slope>1, dr>1, and nStrips>3

Also required track length > 10cm. Examined two variables:

dE variable in track ntuple. Sum of dE / track length

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dE/dx of reconstructed tracks

Upper two plots shows mean values of distribution

Bottom two plots shows Gaussian fit values of distribution.

Fit value Fit value

Mean value Mean value

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dE sum / track length

dE sum/ trk length > 0.18

Low energy proton dE/dx looks like electron or gamma.

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dE sum / track length

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(Backup slides)

dE sum/track length – individual plots

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Gamma

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Gamma

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Electron

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Electron

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Proton