# Presentation: 670673

**Electron high energy calibration**

**Robert Zitoun**
**Stony Brook and LAPP **
** ****CAT Force Meeting**
**May 13, 2003**

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Monte Carlo Energy Resolution

-  Found 3% resolution for 50 GeV electrons (3.1% w/o geo correction)
- i.e.
- Still have to look at Z Monte Carlo. Volker says 2.8%

|  | Run I | Eta corrections p13 |
| --- | --- | --- |
| S | 0.15 | 0.199 ± 0.008 |
| N | 0.16 | 0.42 ± 0.08 |
| C | 0.003 | 0.0076 ± 0.0014 |

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Data

**Data**

- p13.05 + p13.06 + r13.06
- certified CC em objects
- pT >25 GeV
- out of “module boundaries”
- one cluster matched to a track
- Fit it with a Breit-Wigner function		M = 90.2 ± 0.1 GeV
- 	convoluted with a gaussian			 = 3.6 ± 0.1 GeV
- 	BW(MZ, 0 MZ/M0) * N(0, ) + bkg	/M = 4.0%
-  MZ free,  is the resolution		far from 2–2.8%
- M0 and are the PDG values
- allows for scale indeterminacy

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Step by Step Corrections

- Take Cal DataChunk
- Get back to raw ADC
- Apply reco corrections one by one

|  | MZ/GeV | Z/GeV | Z/MZ |
| --- | --- | --- | --- |
| raw ADC | 81.5 | 3.6 | 4.4 |
| non linearity | 86.7 | 3.7 | 4.3 |
| gain correction | 86.6 | 3.6 | 4.2 |
| scale | 86.5 | 3.6 | 4.1 |
| geometric | 90.2 | 3.6 | 4.0 |

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Sampling not done at maximum (~1% effect)
Chan to chan variation different in calibration and physics (~1%)

- Chan to chan variation different in calibration and physics (~1%)

**Better Calibration**

- calibration

- physics

- 4 channels same 
- in layer 3

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Results with Better Calibration

|  | MZ/GeV | Z/GeV | Z/MZ |
| --- | --- | --- | --- |
| reco | 90.2 | 3.6 | 4.0±0.1 |
| calibration timing | 90.2 | 3.6 | 4.0 |
| physics timing | 90.2 | 3.6 | 3.9 |
| amplitude | 90.0 | 3.4 | 3.8 |

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Variations

| before | 90.0 | 3.4 | 3.8±0.1 |
| --- | --- | --- | --- |
| after tuning weights | 90.4 | 3.3 | 3.7 |
| use 2 calweights | 90.4 | 3.3 | 3.7 |
| pulser amplitudes | 90.2 | 3.4 | 3.8 |
| 10  slices | 90.4 | 3.3 | 3.7 |

**Variations**

- Fit calweights to minimize Z width
- 1.04±0.004    0.78±0.016     1.05±0.005    1.02±0.01    0.48±0.06
- highly correlated  corr(1,2) = -0.9    corr(2, 3) = -0.8
- use 2 series of calweights for ||<0.5 or >0.5
- on the 4 CC pulser amplitudes
- fit 4 parameters to minimize Z resolution
- 1.005, 0.997, 1.000, 1.007
- Make 10  slices and fit 10 normalization constants
- ~ 1.00 within <1%

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Shower Size

- Volker’s suggestion:  width agrees with MC but not *z*

|  | M |  | resol | evt # |
| --- | --- | --- | --- | --- |
| all | 90.4 | 3.49 | 3.86 | 3332 |
| z<8 | 89.7 | 3.28 | 3.65 | 645 |
| z<10 | 90.2 | 3.50 | 3.88 | 608 |
| z<14 | 90.8 | 3.73 | 4.10 | 773 |
| z<30 | 90.7 | 3.39 | 3.72 | 576 |

|  | M |  | resol | evt # |
| --- | --- | --- | --- | --- |
| all | 90.4 | 3.49 | 3.86 | 3332 |
| <7 | 90.4 | 3.07 | 3.39 | 351 |
| <9 | 90.4 | 3.43 | 3.79 | 667 |
| <11 | 90.6 | 3.71 | 4.10 | 565 |
| <20 | 89.8 | 3.73 | 4.19 | 569 |

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Module Boundaries

- CC calorimeter made of 32 wedges  = 0.2
- loss of clusters (?)
- loss of energy (no plot)
- 	Oleg Kouznetsov showed that
- 	approx. gaussian energy loss
- 	with  away from “crack”
- 	amplitude 20% 	 = 15 mrad

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003

## Module Boundaries (2)

|  | MZ/GeV | Z/GeV | Z/MZ |
| --- | --- | --- | --- |
|  | 90.4 | 3.3 | 3.7 |
| ||>0.06 | 91.0 | 2.7 | 3.0 |
| ||<0.04 | 87.3 | 2.9 | 3.3 |
| Oleg | 91.1 | 3.1 | 3.4 |
| ampl = 21%  = 15mrad | 91.3 | 3.0 | 3.3±0.13 |

-  = 3.3%

- not yet 2–2.8%
- but more to gain?

- R. Zitoun, Stony Brook and LAPP           EMID Meeting

- 12 March 2003