EM scale using ’s

Vishnu V. Zutshi

BNL

Preamble

decays Important for absolute calibration Non-linearity and offsets Maybe possible with little or no trigger Maybe possible with little or no tracking Affords the possibility of refinement Testing ground for Monte Carlo

Schematic

2 peaks and a valley EM3 is your best chance here Neighbourhood definition You may or may not want to extend the

EM3 clustering to other floors CellNN does extend it to other floors

CellNN

• Each local maxima starts a floor cluster

• An EM cell is defined to have 4 neighbours

• Log weighting for position determination

• Sharing based on a transverse parameterization of the shower

• Angular matching between floor clusters

• Position measurement is key

Just maybe

5 GeV ’s

Asym=abs(e1-e2)/(e1+e2)

Single photons

5 GeV ’sun

corr

ecte

dcorrected

5 GeV ’s

+ E corr.

+ Asym. cut

5 GeV ’sLower Fcluster threshold

5 GeV ’sLower Fcluster threshold

1 GeV photon

2 GeV photons

10 GeV ’s

E/Egen

Ene

rgy

mat

chin

g

10 GeV ’s

E/Egen

unco

rrec

ted corrected

10 GeV ’s

deltaR=sqrt()

5 GeV ’s

5 GeV ’sLower Fcluster threshold

10 GeV ’s

10 GeV ’sP

ositi

on d

eter

min

ed f

rom

ly3

if e

mfr

>0.

2

10 GeV ’s

Single photons

10 GeV ’sL

y3fr

ac>

0.2

and

new

W0’

s

10 GeV ’s

5 GeV ’s

Ongoing…

• W0’s for Fclustering

• Energy corrections

• Fthreshold

• Neighbourhood

• Sharing

• Symmetric mass