!1

TS Distributions of the Positive HAD Sections

TS45 selection

!2

Time Slice Study for EM and HAD Sections of the CMS ZDC:

Ratio of TS4 to TS5PHAD_TS4to5

Entries 1104128

Mean 16.71

Std Dev 6.308 / ndf 2χ 1.432e+04 / 16

Constant 1.850e+02± 8.813e+04

Mean 0.00± 19.08 Sigma 0.0013± 0.9255

10 20 30 40 50 60 70 80 90 100Ratio to TS4 to TS5

1

10

210

310

410

510

coun

ts

PHAD_TS4to5Entries 1104128

Mean 16.71

Std Dev 6.308 / ndf 2χ 1.432e+04 / 16

Constant 1.850e+02± 8.813e+04

Mean 0.00± 19.08 Sigma 0.0013± 0.9255

PHAD1 TS4to5 RatioPEM2_TS4to5

Entries 1380160

Mean 17.95

Std Dev 8.396 / ndf 2χ 6682 / 9

Constant 1.014e+02± 4.026e+04

Mean 0.00± 21.28 Sigma 0.004± 1.566

10 20 30 40 50 60 70 80 90 1001

10

210

310

410

coun

ts

PEM2_TS4to5Entries 1380160

Mean 17.95

Std Dev 8.396 / ndf 2χ 6682 / 9

Constant 1.014e+02± 4.026e+04

Mean 0.00± 21.28 Sigma 0.004± 1.566

PEM2 TS4to5 Ratio

PHAD3_TS4to5Entries 1104128

Mean 18.25

Std Dev 7.074 / ndf 2χ 1.046e+04 / 15

Constant 1.023e+02± 3.125e+04

Mean 0.00± 20.78 Sigma 0.003± 1.245

10 20 30 40 50 60 70 80 90 100Ratio to TS4 to TS5

1

10

210

310

410

coun

ts

PHAD3_TS4to5Entries 1104128

Mean 18.25

Std Dev 7.074 / ndf 2χ 1.046e+04 / 15

Constant 1.023e+02± 3.125e+04

Mean 0.00± 20.78 Sigma 0.003± 1.245

PHAD3 TS4to5 RatioPHAD4_TS4to5

Entries 1104128

Mean 17.42Std Dev 6.675

/ ndf 2χ 4647 / 16

Constant 6.736e+01± 1.479e+04

Mean 0.0± 19.6 Sigma 0.004± 1.316

10 20 30 40 50 60 70 80 90 100Ratio to TS4 to TS5

1

10

210

310

410coun

ts

PHAD4_TS4to5Entries 1104128

Mean 17.42Std Dev 6.675

/ ndf 2χ 4647 / 16

Constant 6.736e+01± 1.479e+04

Mean 0.0± 19.6 Sigma 0.004± 1.316

PHAD4 TS4to5 Ratio

TS Ratio cut at 8.0

!3

Correlation of Ratio 4to5 among HAD Sections

5 10 15 20 25 30PHAD1 TS Ratio

5

10

15

20

25

30

PHAD

2 TS

Rat

io

PHAD2vsPHAD1 TS45Ratio

Entries 1104128Mean x 19.16Mean y 18.53Std Dev x 3.08Std Dev y 3.005

0

500

1000

1500

2000

2500

PHAD2vsPHAD1 TS45Ratio

Entries 1104128Mean x 19.16Mean y 18.53Std Dev x 3.08Std Dev y 3.005

TS45 Ratios

5 10 15 20 25 30PHAD1 TS Ratio

5

10

15

20

25

30

PHAD

4 TS

Rat

io

PHAD4vsPHAD1 TS45Ratio

Entries 1104128Mean x 19.03Mean y 18.62Std Dev x 3.304Std Dev y 2.804

0

100

200

300

400

500

PHAD4vsPHAD1 TS45Ratio

Entries 1104128Mean x 19.03Mean y 18.62Std Dev x 3.304Std Dev y 2.804

TS45 Ratios

!4

Neutron Identification

!5

Mysterious Case of the Shifting Beam Position

Mean X position as determined by the 5 EM

sections (in units cm from center)

Question - Why is the region with the neutron peaks offset from the more central events??

!6

Positive RPD TS 45/456 Ratios

“Good” data cut >0.6

These 3 have a very different fC distribution

Pos RPD1 Pos RPD5

Pos RPD16

Pos RPD14 Pos RPD2