of 3
EPAPS Material
The following includes supplementary material for the Electronic Physics Auxiliary Publication Service.
continuum-trained BDT output
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
Entries / 0.03
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
Data
0
B
0
B
-
e
+
e
-
B
+
B
-
e
+
e
q
q
-
e
+
e
-4
= 1 GeV, BF = 10
a
m
-trained BDT output
B
B
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
Entries / 0.03
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
Data
0
B
0
B
-
e
+
e
-
B
+
B
-
e
+
e
q
q
-
e
+
e
-4
= 1 GeV, BF = 10
a
m
FINAL SELECTIONS
25
Adopted same BDT cuts for all signal masses
Cut of > 0.13 on continuum-trained BDT output, > 0.15 on
-trained BDT output
e
+
e
!
B
+
B
<latexit sha1_base64="CnafgCsHkEUsB5cDqNWlptKvNfE=">AAACAXicbVDLSgNBEJyNrxhfq14EL4NBEELCrgTUW4gXjxHMA5LdMDvpJENmH8zMKmGJF3/FiwdFvPoX3vwbJ8keNLGgoajqprvLiziTyrK+jczK6tr6RnYzt7W9s7tn7h80ZBgLCnUa8lC0PCKBswDqiikOrUgA8T0OTW90PfWb9yAkC4M7NY7A8ckgYH1GidJS1zwCtwBusSPYYKiIEOEDrrqFqlvsmnmrZM2Al4mdkjxKUeuaX51eSGMfAkU5kbJtW5FyEiIUoxwmuU4sISJ0RAbQ1jQgPkgnmX0wwada6eF+KHQFCs/U3xMJ8aUc+57u9IkaykVvKv7ntWPVv3QSFkSxgoDOF/VjjlWIp3HgHhNAFR9rQqhg+lZMh0QQqnRoOR2CvfjyMmmcl+xy6eq2nK9U0ziy6BidoDNkowtUQTeohuqIokf0jF7Rm/FkvBjvxse8NWOkM4foD4zPH9yJleI=</latexit>
FIG. 6: Boosted decision tree classifier scores for ALP candidates in data, signal MC with
m
a
= 1 GeV normalized to a
branching fraction of 10
4
, and background MC normalized to the data luminosity. The classifier scores are for BDTs trained
on (left) continuum MC; (right)
B
+
B
MC. The selections used in the analysis are indicated for each distribution by the arrow.
9
Events / ( 0.004 GeV )
0
500
1000
(GeV)
a
a
m
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Pull
-4
-2
0
2
Events / ( 0.005 GeV )
0
50
100
150
(GeV)
a
a
m
0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7
Pull
-4
-2
0
2
4
Events / ( 0.0055 GeV )
0
20
40
60
(GeV)
a
a
m
0.7
0.8
0.9
1
1.1
1.2
Pull
-2
0
2
Events / ( 0.005 GeV )
0
5
10
15
20
(GeV)
a
a
m
1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65
Pull
-2
0
2
Events / ( 0.008 GeV )
0
5
10
15
(GeV)
a
a
m
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
Pull
-2
0
2
Events / ( 0.008 GeV )
0
5
10
15
(GeV)
a
a
m
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
Pull
-4
-2
0
2
Events / ( 0.0064 GeV )
0
5
10
(GeV)
a
a
m
2.7
2.8
2.9
3
3.1
3.2
3.3
Pull
-4
-2
0
2
Events / ( 0.005 GeV )
0
5
10
(GeV)
a
a
m
3.25 3.3 3.35 3.4 3.45 3.5 3.55 3.6 3.65 3.7 3.75
Pull
-2
0
2
Events / ( 0.0036 GeV )
0
5
10
(GeV)
a
a
m
3.85
3.9
3.95
4
4.05
4.1
4.15
Pull
-2
0
2
Events / ( 0.003 GeV )
0
5
10
15
(GeV)
a
a
m
4.1
4.15
4.2
4.25
4.3
4.35
4.4
Pull
-2
0
2
4
Events / ( 0.0021 GeV )
0
5
10
(GeV)
a
a
m
4.4
4.45
4.5
4.55
4.6
Pull
-4
-2
0
2
Events / ( 0.00068 GeV )
0
2
4
6
(GeV)
a
a
m
4.72
4.73
4.74
4.75
4.76
4.77
4.78
Pull
0
2
4
FIG. 7: Fits of our background model to data for a sample of fit intervals used in the ALP search. The green line indicates
the best-fit background model, and the points represent data. The fit interval width is determined by the signal resolution as
outlined in the main-body text.
10
(GeV)
a
m
0
0.5
1
1.5
2
2.5
S
N
-200
-100
0
100
200
= 1 mm
a
τ
c
(GeV)
a
m
0
0.5
1
1.5
2
2.5
S
S
-5
0
5
(GeV)
a
m
0
0.5
1
1.5
2
2.5
S
N
-200
-100
0
100
200
= 10 mm
a
τ
c
(GeV)
a
m
0
0.5
1
1.5
2
2.5
S
S
-5
0
5
(GeV)
a
m
0
0.5
1
1.5
2
2.5
S
N
-200
-100
0
100
200
= 100 mm
a
τ
c
(GeV)
a
m
0
0.5
1
1.5
2
2.5
S
S
-5
0
5
FIG. 8: The distribution of signal events (
N
s
)andlocalsignalsignificance(
S
s
) from fits as a function of
m
a
for ALP proper
decay lengths of 1 mm, 10 mm, and 100 mm. The vertical gray bands indicate the regions excluded from the search in the
vicinity of the
0
,
,and
0
masses.
11