Supplementary Material for
"Measurement of the scintillation efficiency for nuclear recoils in liquid argon under electric fields up to 3 kV/cm"
(M.Kimura et al., Phys.Rev.D 100 032002 (2019))

Article

• link to Phys.Rev.D
• link to arXiv
• link to inspire

Materials

• Leff.C
• LeffwQy.C
• Figure12.pdf
• Figure13_top.pdf
• Figure13_bottom.pdf

Figure 12: Scintillation efficiencies Leff as a func- tion of the NR energy measured in this work. The colored solid lines represent the results from this work, and the cor- responding dashed lines are extrapolations.

Figure 13: Top: Comparison with previous Leff measurements (SCENE [8], ARIS [11], and DarkSide-50 [10]) at null field. The black solid line is the result from this work (same as in Fig. 12), and the orange band represents the total uncertainty on Leff . Bottom: The comparison under electric fields of 0.2 and 1.0 kV/cm. The corresponding colored bands represent total uncertainty on Leff , including the uncertainty from g2/g1.

Instruction

You can draw the functions in Figure 12 by "Leff.C" using ROOT framework. Belows are the brief instrunction of this code.

• You can draw Leff function as following:
  $ root
> .L Leff.C
> Leff(inputF, "manual", inputkB, inputAlpha_0, inputD_Alpha, inputGamma, inputDelta)
where "inputF" is the input field in kV/cm unit, inputkB is the parameter k_B in the NR model, inputAlpha_0 is the α₀, inputD_Alpha is the D_α, inputGamma is the γ, and the inputDelta is the δ.
  
  
• If you run the code with the option "BestFit", the code returns the function with the best fit parameters.
In this case you should only input the magnitude of applied electric field in kV/cm unit. For example, below commands returns the function in F = 3.0 kV/cm.
$ root
> .L Leff.C
> Leff(3.0)


• Furthermore, you can draw the error band described in the article.
  Following is the commands to get the error band in F = 3.0 kV/cm.
  $ root
> .L Leff.C
> Leff_wBand(3.0)

  
• If you run the code with other options listed below, the code returns the functions with parameters representing systematic uncertainties. See detail for Sec.VI in the paper.
  The options are :
  "E-calib_+03", "E-calib_-03", "TOFarm_+1", "TOFarm_-1", "TOFt0_+1", "TOFt0_-1", "g2g1_+20", and "g2g1_-20".
  For example,
  $ root
> .L Leff.C
> Leff(3.0, "E-calib_+03")

  
• The ionization yield Qy [e-/keV] is also predicted by the model and parameters.
  The Qy curve is drawn as follows;
  $ root
> .L LeffwQy.C
> LeffwQy(0.2)