# dQ/dx-d/Edx Calibration¶

**Table of contents**- dQ/dx-d/Edx Calibration
- Contact Persons:
- Ideas
- Procedure
- Resources

# Contact Persons:¶

- Varuna Meddage, Tingjun Yang (Framework, tools)

- MCC8
- Varuna Meddage
- Davide S. Porzio, Yun-Tse Tsai (Run 3 data)

- MCC9
- Maya Wospakrik, Wanwei Wu

# Ideas¶

We use through-going and stopping muons to determine the relative response correction factors - XYZ (T) of the LArTPC detector and want the detector response to the charge collection to be uniform over space and time.

## The detector response is not uniform because:¶

- Dead wire regions and misconfigured ASICs
- Space charge effects
- Electron attenuation and diffusion
- Recombination
- Temporal variations

By unifying the detector response, we mean to calculate the correction factors for taking care of those effects.

# Procedure¶

## Prerequisites (in the following order)¶

- Updated bad channel database (refer: Calibration Database)
- Updated ASIC misconfiguration database (refer: Calibration Database)
- Good run list (refer: Good Run Selection)
- Stage Reco 1 sample (from Ext. BNB)
- Stage Reco 2 (Calorimetry reconstruction on the Reco 1 sample) sample

## Step by Step¶

**1. YZ Correction for dQ/dx values:**

- Aim to remove the effects from the misconfigured ASICs, space charges, and transverse diffusion.
- see example plot below (from docdb: 19039)

**2. X Correction for dQ/dx values:**

- Deal with electron attenuation, longitudinal diffusion, space charge effects, and recombination.
- see example plot below (from docdb: 19039)

One can calculate the XYZ correction using: XYZ_correction = YZ_correction * Drift direction (X) correction.

**3. T Correction for dQ/dx (in addition to XYZ correction):**

- Study the variation in global dQ/dx median over time to derive the timing corrections.
- see example plot below (from docdb: 19039)

One can obtain the total correction for dQ/dx now: Total correction = Time correction * XYZ correction.

**4. dE/dx calibrations**

- Once the data sets are corrected by the total correction (dQ/dx), then we try to convert all dQ/dx values to dE/dx values.
- See the formula and plot below (from docdb: 9248). Here the calibration constant was chose as 4.400 e-3.

- dE/dx distribution is then fitted with a Landau convoluted Gaussian and extracted the MPV (most probable value) for dE/dx.
- Ideally MPV value should be peaked around 1.7 MeV/cm (MIP energy for a 5 GeV Muon).

## Post Steps¶

- Apply these corrections and calibration constant to data and see whether we can use dE/dx information for particle identification.
- See example for proton identification below (from docdb: 9248)

# Resources¶

## Notes/Publications:¶

- Detector Calibration Public Note: docDB # 15584
- Detector Calibration Internal Note: docDB # 14754
- Detector Calibration of Run 3 Data Internal Note: docdb # 18333

## Documents for methods:¶

- Update on Calibrating the detector using cosmic Muons: docDB # 9248