Electron selection parameterization

PS, 1-10GeVHlushchenko Olena

28.03.2014

Starting point

• The analysis used PS runs in the momentum range 1-10GeV• Both Cherenkov A and B used CO2 gas• One should take into account that SPS runs at 10-300GeV runs used

He instead of CO2• Pressure settings of the two Cherenkov detectors for all mixed hadron

runs:

Electron selection

• For the next selection only runs with Cherenkov pressure BELOW the pion threshold were taken. Some 9 GeV runs where excluded from the analysis as the pressure in the CherenkovB detector was set up above the pion threshold .

• Runs with issues have been removed: 660067,660068,660052.• For all runs efficiency to have an electron signal with Cherenkov is close too 100%• For runs >=4 GeV the pressure in Cherenkov is above the muon threshold

pressure.• For those runs, when both Cherenkov detectors have a signal we can expect both:

electrons and muons• In 1-3 GeV runs the pressure in Cherenkov is lower that is needed to have a muon signal-> pure electron selection [1] ///• In 3-10GeV runs we can have a rather pure electron selection by asking for two

Cherenkov signals combined with the density cuts in the calorimeter

For the 4GeV runs we can also have some separation for muons, as the CherenkovA pressure is set up below the threshold pressure for 4 GeV muons and CherenkovB above.

Run Numbers

Beam Mom

CherenkovA,bar

CherenkovB, bar

660186 4 0.82 2.98660189 4 0.82 2.98660190 4 0.82 2.97660191 4 0.82 2.96660192 4 0.82 2.95660192 4 0.82 2.95

DHCAL identification criteria, used to reject muons• There were no interaction layer• Number of center of all hits in the z-axis is higher then 20• Total number of hits in all layers is bigger than 30• There were no electronics errors (box events etc.)• The number of hits in last 4 layers is higher than 2• There were less than 2,25 hits per layer in average

DHCAL identification criteria, used to select electrons• First interaction was in second or third layer• Number of center of all hits in the z-axis is less than 10• There were no electronics errors (box events etc.)• The number of hits in last 12 layers is less than 2• There were more than 5 hits per layer on average

DHCAL identification criteria, used to reject pions• First interaction was between 1st and 11th layer• Number of hits is greater than 20• There were no electronics errors (box events etc.)• There were more than 2 hits per layer on average

Efficiency

• This all gives us better approach for calculation of the efficiency to identify an electron with DHCAL on tag-and-probe method• Tag—pure electron events obtained with Cherenkov+muon cuts• Probe—reconstructed with DHCAL electrons• Efficiency:

• - Number of the DHCAL and CHERENKOV signals for electrons• - Number for CHERENKOV signals for electron

&& &

&

DHCAL CherenkovA B

CherenkovA B

N

N

𝑁𝐷𝐻𝐶𝐴𝐿&& h𝐶 𝑒𝑟𝑒𝑛𝑘𝑜𝑣𝐴&𝐵

𝑁 h𝐶 𝑒𝑟𝑒𝑛𝑘𝑜𝑣𝐴& 𝐵

• PURITYCHEKFORCHERENKOVWITHDHCAL.PY

Electron reconstruction

Beam mommentum GeV

Num. CherenkovA&B Num.DHCAL

Num. CherenkovA&B&&DHCAL Efficiency

1 315019 1458 1434 0,0045521062 185662 15274 14517 0,0781904753 83531 17178 15155 0,1814296494 54997 22516 15674 0,2849973635 57352 22729 11763 0,2051018276 34137 24317 8687 0,2544746177 19875 32283 5774 0,2905157238 8455 22674 2379 0,2813719699 5171 25313 1294 0,250241733

10 2071 24043 549 0,265089329

Electrons amount visualisation

• For the next slides one can see, that starting from the 4 GeV beam momentum runs the muons start to apper in the Cherencov selection, where both Cherenkov worked.• Code ELECTRONIAYERNUMdISTRIB.PY

fElectron reconstruction with/without cuts

• electronsDensEnergycut.py

• 1 GeV run• No separation in 1st row• Pure electrons on 2nd row• Muons and pions in 3rd row

• 2 GeV run• No separation in 1st row• Pure electrons on 2nd row• Muons and pions in 3rd row

• 3 GeV run• No separation in 1st row• Pure electrons on 2nd row• Muons and pions in 3rd row

• 4 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

• 5 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

• 6 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

• 7 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

• 8 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

• 9 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

• 10 GeV run• No separation in 1st row• Electrons with muons on 2nd row• Muons and pions in 3rd row

Electron calibrated number of hits

• The center points of energy branch for electrons peak.• Error bars is RMS• 2 fits: exponential, line• Electrons were selected with

both Cherenkov gigving signal, layerEnergy>0 and hitDensity>2,25 for energies above 4 GeV (included)

0 2 4 6 8 100

10

20

30

40

50

60

70

80

Calib

rate

d num

ber

of h

its fo

r ele

ctro

ns

Beam momentum (GeV)

Equation y = A + B*x

Adj. R-Square 0,98024

Value Standard Error

Normilized number of hits for electrons

A 8,61419 1,24647

Normilized number of hits for electrons

B 5,93966 0,2808

Equation y = A1*exp(-x/t1) + y0

Adj. R-Square 0,99845

Value Standard Error

Normilized number of hits for electrons

y0 94,36513 6,0458

Normilized number of hits for electrons

A1 -90,60393 5,57898

Normilized number of hits for electrons

t1 9,41836 1,00952

Electron calibrated fitted number of hits• The center points of energy

branch for electrons peak fitted with gaus.• Sigma error bars• 2 fits: exponential, line• Electrons were selected with

both Cherenkov gigving signal, layerEnergy>0 and hitDensity>2,25 for energies above 4 GeV (included)

0 2 4 6 8 100

10

20

30

40

50

60

70

80

fitte

d w

ith g

aus

mea

n

Beam momentum (GeV)

fitted with gaus mean Line Fit of fitted with gaus mean ExpDec1 Fit of fitted with gaus mean

Equation y = A + B*x

Adj. R-Square 0,9843

Value Standard Erro

fitted with gaus mean

A 8,64979

1,13885

fitted with gaus mean

B 5,79207

0,24363

Equation y = A1*exp(-x/t1) + y0

Adj. R-Square 0,99942

Value Standard Error

fitted with gaus mean

y0 96,30168 4,17964

fitted with gaus mean

A1 -92,2565 3,87966

fitted with gaus mean

t1 10,08973 0,71782

Electron hitdensity

• The center points of hitDensity for electrons peak.

• Error bars RMS• 3 fits: polynomial,

exponential, line, fitted with Chi-squared

• Electrons were selected with both Cherenkov gigving signal, layerEnergy>0 and hitDensity>2,25 for energies above 4 GeV (included)

0 2 4 6 8 10

1

2

3

4

5

6

7

8

9

10

11

hit d

ensi

ty fo

r el

ectron

s

beam momentum

B Parabola Fit of B ExpDec1 Fit of B Line Fit of B

Equation y = A + B*x + C*x̂ 2

Adj. R-Squ 0,97057

Value Standard Er

B A 2,8058 0,36661

B B 0,8975 0,16056

B C -0,029 0,01407

Equation y = A1*exp(-x/t1) + y0

Adj. R-Square 0,97362

Value Standard Error

B y0 11,62452 1,92603

B A1 -9,04418 1,60838

B t1 8,49677 3,35065

Equation y = A + B*x

Adj. R-Squa 0,95839

Value Standard Err

B A 3,4516 0,23094

B B 0,5713 0,03959

What should be next

• Repeating the analysis in higher energies for other particles • Parameterize the cuts for DHCAL selections for other types of

particles• Check how did the efficiency change with applying new cuts

Appendix 1. Runs with pressure above the thredhold for Pions with Cherenkov detectorsenergy = 9.0number=660054 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660055 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660056 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660057 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71

number=660058 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660059 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660060 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660061 A Presure(real)-Presure(thed)=1.71 B Presure(real)-Presure(thed)=1.71number=660066

A Presure(real)-Presure(thed)=1.96 B Presure(real)-Presure(thed)=1.96number=660070 A Presure(real)-Presure(thed)=0.71 B Presure(real)-Presure(thed)=0.71

Runnumbers = [660054, 660055, 660056, 660057 660058, 660059, 660060, 660061, 660066,

660070]

Appendix 2. Efficiency list

• [0.004552106380884963, 0.07819047516454633, 0.18142964887287355, 0.2849973634925541, 0.20510182731203794, 0.25447461698450363, 0.29051572327044023, 0.2813719692489651, 0.25024173274028233, 0.2650893288266538]