The

Beg

inni

ngs

Of A

Par

ticle

F

low

Alg

orith

m

�

Qui

ck s

tatu

s up

date

on

crys

tal E

CA

L

�

Gen

eral

com

men

ts

�

Cur

rent

sta

te o

f the

cod

e

�

Som

e pl

ots

�

May

ski

p so

me

if pr

esse

d fo

r tim

e

Mat

thew

Cha

rles,

U. I

owa

2003

-09-

29

Cry

stal

EC

AL

hard

war

e st

udy

�

Bei

ng d

one

by W

illia

m C

audy

(U

iow

a)

�

Usi

ng h

igh-

yiel

d P

bWO

4 cry

stal

s, s

ourc

e

�

Bee

n ta

king

dat

a vi

a os

cillo

scop

e (s

low

)

�

Fin

ally

sol

ved

DA

Q p

robl

em F

riday

;w

ill s

tart

taki

ng d

ata

via

NIM

cra

te.

�

Man

y th

anks

to P

eter

Kim

.

Cry

stal

EC

AL

hard

war

e st

udy

Pul

se h

eigh

t dis

trib

utio

nw

ith s

ourc

e (w

hite

)w

ithou

t sou

rce

(red

)ta

ken

over

sam

e tim

e in

terv

al

Par

ticle

flow

alg

orith

m

�

Bas

ic p

roce

ss:

�

Loca

te a

clu

ster

(po

ssib

ly s

eede

d)

�

“Fit”

it w

ith a

n ap

prop

riate

sha

pe

�

Sto

re r

esul

ts

�

Ass

ign

ener

gy/h

its fr

om th

e C

AL

�

Itera

te

�

Opt

imal

use

of i

nfor

mat

ion:

�

Sta

rt w

ith m

ost k

now

n/pr

edic

tabl

e cl

uste

rs

�

Mov

e on

to th

ose

with

less

see

d in

form

atio

n

�

Mov

e on

to th

ose

with

no

seed

info

rmat

ion

Flo

w a

lgor

ithm

thou

ghts

Whe

re to

sta

rt

�

MIP

-like

trac

ks, s

eede

d w

ith p

ositi

on a

nd

dire

ctio

n in

fo fr

om tr

acke

r

�

char

ged

pion

s, m

uons

, ...

�

Sho

wer

s w

ith k

now

n po

s. a

nd d

ir.

�

elec

tron

s

�

char

ged

trac

ks th

at s

how

er in

side

the

CA

L

�

Clu

ster

s w

ith s

ome

seed

info

rmat

ion

�

scat

tere

d/fr

agm

ente

d tr

acks

�

Oth

ers

�

gam

mas

etc

.

�

Neu

tral

had

rons

MIP

s: W

hat's

impl

emen

ted

�

Che

atin

g: F

ollo

win

g on

e tr

ack

at a

tim

e

�

See

d us

ing

trut

h in

form

atio

n

�

Sim

ple

trac

k ex

trap

olat

ion

algo

rithm

�

Firs

t fe

w la

yers

(un

til 4

laye

rs a

lread

y hi

t) ju

st

exte

nd M

C s

eed

in a

str

aigh

t lin

e

�

Afte

r th

at, s

trai

ght l

ine

from

hits

in la

st fe

w

laye

rs (

up to

6),

don

e w

ith p

rinci

pal a

xis

(he

p.lc

d.re

con.

clus

ter.

util.

Abs

trac

tClu

ster

)

�

Pic

k up

nea

rby

hits

in s

ame

laye

r

�

Will

ski

p ga

ps o

f up

to n

laye

rs (

usin

g 2)

�

Som

e pl

ots

(e.g

. dE

/dx)

Wha

t's n

ot im

plem

ente

d ye

t

�

Tot

al e

nerg

y de

posi

ted

by c

lust

er

�

Ene

rgy

subt

ract

ion

from

CA

L

�

How

muc

h to

take

? S

houl

d be

rou

ghly

con

sist

ent

with

MIP

, but

allo

w fo

r flu

ctua

tions

.

�

Ref

inin

g (s

econ

d pa

ss to

impr

ove

the

fit)

�

Re-

seed

ing

for

subs

eque

nt c

lust

ers

�

Rec

o in

the

pres

ence

of n

oise

, oth

er c

lust

ers

�

Nee

d to

inco

rpor

ate

Clu

ster

Ana

lysi

s fir

st

�

Tra

cks

cros

sing

from

bar

rel t

o/fr

om e

ndca

p

�

HC

AL

Wha

t's n

ext

�

Und

erst

andi

ng w

hy w

e lo

se c

lust

ers

�

Ref

ine/

seco

nd p

ass

�

Ron

's c

lust

er a

naly

zer

�

Add

noi

se, r

est o

f eve

nt

�

How

do

thre

shol

d cu

ts a

ffect

thin

gs?

�

Will

we

need

to a

llow

for

larg

er g

aps?

�

Pic

k th

resh

olds

�

Ene

rgy-

subt

ract

ion

algo

rithm

Rec

onst

ruct

a c

lust

er w

ith >

0 hi

ts

Par

ticle

dep

osite

d no

ene

rgy

in E

CA

L

MC

Par

ticle

did

n't r

ecor

d w

here

part

icle

ent

ered

CA

L

Par

ticle

dep

osite

d en

ergy

in

EC

AL

but w

e di

dn't

find

it

Pio

ns

panp

yZH

120-

0-50

0.si

o

Unr

econ

stru

ctab

le c

lust

ers?

�

Whe

re d

o th

e cl

uste

rs w

ith n

o E

CA

L hi

ts

com

e fr

om?

�

Whe

re d

o th

e cl

uste

rs w

ith E

CA

L hi

ts b

ut

no v

alid

see

d po

int/m

omen

tum

com

e fr

om?

Pio

ns w

ith n

o E

CA

L hi

ts: d

ecay

poi

nt

End

cap

End

cap

Bar

rel

Pio

ns w

ith E

CA

L hi

ts b

ut n

o se

ed p

oint

/mom

entu

m

End

cap

End

cap

Bar

rel

Muo

nsP

artic

le d

epos

ited

no e

nerg

y in

EC

AL

Par

ticle

dep

osite

d en

ergy

in

EC

AL

but w

e di

dn't

find

it

MC

Par

ticle

did

n't r

ecor

d w

here

part

icle

ent

ered

CA

L

Why

so

man

y m

uons

with

no

hits

in th

e E

CA

L?

Onl

y pl

ottin

g re

sults

for

trac

ks th

at

depo

sit

ener

gy in

E

CA

LW

e fa

iled

to fi

nd th

e se

ed(a

ppro

x 15

%)

Eve

ry la

yer

in E

CA

L hi

t(a

ppro

x 60

%)

Muo

ns: #

laye

rs in

re

cons

truc

ted

clus

ters

Why

so

man

y m

uons

bei

ng

mis

sed/

drop

ped?

All

low

m

omen

tum

.

All

ente

r th

e en

dcap

Nea

rly a

ll sh

ower

(!)

... s

o m

aybe

be

ing

scat

tere

d or

sho

wer

ing

befo

re fi

rst

activ

e la

yer.

Not

ve

rifie

d ye

t.

Onl

y pl

ottin

g re

sults

for

trac

ks th

at d

epos

it en

ergy

in E

CA

L

smal

l pea

k (n

ot s

een

for

muo

ns)ap

prox

33%

appr

ox 5

%

Pio

ns

Why

the

peak

afte

r 4

laye

rs?

(1 /

3)

�

Whe

n th

ere

are

< n

laye

rs h

it pr

evio

usly

, we

extr

apol

ate

prev

ious

bes

t-gu

ess

dire

ctio

n. W

hen

ther

e ar

e >=

n

laye

rs h

it, w

e sw

itch

to u

sing

prin

cipa

l axi

s of

hits

for

dire

ctio

n. D

efau

lt is

n

= 4

. Wha

t if

n =

5?

peak

at 5

Why

the

peak

afte

r 4

laye

rs?

(2 /

3)

�

... s

o it'

s al

gorit

hmic

. Dire

ctio

n es

timat

e fa

ils if

the

clus

ter

is q

uite

err

atic

.

�

Why

is it

see

n in

pio

ns a

nd n

ot m

uons

? B

ecau

se p

ions

are

mor

e lik

ely

to s

how

er.

�

Ver

ify b

y pl

ottin

g do

t pro

duct

:

[initi

al m

omen

tum

].[es

timat

ed m

om]

for

part

icle

s lo

st a

fter

findi

ng h

its in

n

la

yers

, for

n

= 4

,5,6

...

Why

the

peak

afte

r 4

laye

rs?

(3 /

3)

dE/d

x

�

Goo

d cr

oss-

chec

k

�

Will

be

used

for

a cu

t on

ener

gy d

epos

ited

in c

ells

�

Cal

cula

ted

for

core

hit

in e

ach

laye

r, u

sing

be

st e

stim

ate

of tr

ajec

tory

.

MIP

pea

k

Muo

ns: d

E/d

x