May 1-3, LHC 2003 V. Daniel Elvira 1

CMS: Hadronic Calorimetry &

Jet/ PerformanceV. Daniel Elvira

Fermilab

TE

May 1-3, LHC 2003 V. Daniel Elvira 2

HO HE ( extend to ||=3) HB (||<1.3)

The CMS Detector

HF (extend to ||=5)

8.6 m

May 1-3, LHC 2003 V. Daniel Elvira 3

The CMS Physics

H jet(H-> ), (mH < 120) H-> inclusive, qqH (H->WW*-> ll), qqH (H->-> l -jet),WH-> l , ttH (H->bb), qqH (H-> ), WH-> l bb

TE

qq (H -> ZZ*/WW* -> llll, ll) (120 < mH < 500)

Example: SM Higgs discovery channels

The search for the Higgs boson, SUSY particles, new phenomena constitute the core of the CMS physics program

HCal crucial for jet and measurements (signature)TE

May 1-3, LHC 2003 V. Daniel Elvira 4

HB Calorimeter (central)

Sampling calorimeter: brass (passive) & scintillator (active)Coverage: ||<1.3Depth: 5.8 int (at =0) segmentation: x resolution: ~ (120 / + 4)% 0.087x0.087

20o

E

Completed & assembled 17 layers longitudinally, x = 4 x 16 towers

May 1-3, LHC 2003 V. Daniel Elvira 5

HO Calorimeter (outer)Total number of int till the last sampling layer of HB is ~8.HO: 2 scint. layers around first layer (extend to~11.8 int )

~ 5% of a 300 GeV energy is leaked outside the HB

HO improves resolution by ~10% at 300 GeV & linearity

Test Beam 2002

Ring 0

Ring 1

Ring 2

May 1-3, LHC 2003 V. Daniel Elvira 6

HE Calorimeter

Completed, assembled, HE-1 installed

Sampling calorimeter: brass (passive) & scintillator (active)Coverage: 1.3<||<3Depth: 10 int (at =0) segmentation: x resolution: ~ (120/ + 4)% 0.087x0.087

E

20o

19 layers longitudinally

May 1-3, LHC 2003 V. Daniel Elvira 7

HF CalorimeterSteel absorbers, embedded quartz fibres // to the beam Fast (~10 ns) collection of Cherenkov radiation.

Coverage: 3<||<5 segmentation: x Depth: 10 int 10o x 13 towers

Fibre insertion finished by Nov 03

May 1-3, LHC 2003 V. Daniel Elvira 8

HF CalorimeterHF used to tag forward jets in qq (H -> ZZ*/WW* -> llll, ll) Higgs searches, to reduce QCD background by a factor of ~10.

120% at 50 GeV 20% at 400 GeV

HF acceptance for tagging quarks of ET>30 GeVNo q 1 q 2 q’s 0.47 0.46 0.07

May 1-3, LHC 2003 V. Daniel Elvira 9

ECal 7x7 Crystal Matrix (movable)

2 HCal HB Modules

HO Panels

Aluminum Slab

HCal 2002 Test Beam

beam

Moving table

Small scale experiment to demonstrate that HCal works: 49 ECal crystals, 144 HB channels, 16 HO channels.

Over 100 Million

Events!

-: 225 GeV

e-: 20,30,50,100 GeV

-: 20,30,50,100,

300 GeVRead out with a 29.6 ns period

May 1-3, LHC 2003 V. Daniel Elvira 10

HBL s)

225 GeV muon

beam

16 )

HBL s)

16 )

beam

100 GeV electron

AD

C

counts

HBL s)

16 )

beam

300 GeV pion

AD

C

counts

HCal 2002 Test Beam

97% of energy contained in a 3x3 crystal matrix

99% of energy contained in a 5x5 HB tower matrix

May 1-3, LHC 2003 V. Daniel Elvira 11

Attenuation ~ 50%

Att. (A

rbit.

Un

its)

HCal 2002 Test Beam

HB Pulse out of the QIE ( Charge Integration Electronics) mean :

0.875 ADC = 260 MeV

HB Pedestal sigma distribution

Response attenuation as the signal travels longer distances to the QIE from high towers

(,)=(1,1)

Time(ns)

300 GeV pions

Noise in HB

May 1-3, LHC 2003 V. Daniel Elvira 12

Measurement of HO muon signal for RPC trigger (Goal: use the HO as part of muon trigger)

HCal 2002 Test Beam

beam

HB

beam

HO

HO SignalPedestal Subtracted

Pedestal Distribution

225 GeV muon

May 1-3, LHC 2003 V. Daniel Elvira 13

Based on 1-5,000 events onto the ()=(6,2) tower of the HB and crystal 25 of the ECal matrix

TB02 Simulation (OSCAR/G4 )

Crystal 25

An accurate Monte Carlo simulation is critical: detector design & calibration, data analysisValidation of GEANT4/OSCAR by June03 for

M.C. production towards DC04 & physics TDR)

May 1-3, LHC 2003 V. Daniel Elvira 14

Angle view of the full TB02 detector

10 GeV electron

HB

ECalHO

Beam Line

HO

HB

ECal

Beam Line

TB02 Simulation (OSCAR/G4 )

100 GeV pion

May 1-3, LHC 2003 V. Daniel Elvira 15

Pion peak

Muon background

Background subtracted pion peak

E/E = 20.3%

TB02: E/E and e/

50 GeV pions

Pions showering in the crystals

Data energy resolution for 50 GeV pions (Ecal+HB, no HO)

May 1-3, LHC 2003 V. Daniel Elvira 16

TB02: E/E and e/

The agreement is excellent in all the energy range

Shape difference: e/h (e.m. & nuclear x-sec), leakage……?

Data systematic error analysis in progress

Validate GEANT4 physics models

Resolution Linearity

May 1-3, LHC 2003 V. Daniel Elvira 17

Goals for the 2002 HCal testbeam,•Operation of 144 channels at 33.79 MHz•Absolute calibration using beam/source•Determination of pulse shape•Measurement of attenuation•Determination of Layer-0 weighting•Measurement of muon signal (HO) for RPC trigger•Control of HV, front end, and moving source

have been met!

Move on to TB03... Repeat TB02 tests,…plus…, local synch in all channels, HB-HE boundary, signal for calibration, remote monitoring & analysis

Summary on TB Program

May 1-3, LHC 2003 V. Daniel Elvira 18

Jet & ResolutionTEPYTHIA + CMSIM + ORCA single jets (R=0.5 cone algorithm)

Squarks/gluinos of M~500 GeV decaying to jets +

TE

39% at 20 GeV 12% at 100 GeV

May 1-3, LHC 2003 V. Daniel Elvira 19

Mass Resolution gg -> -> hh -> 2 + 2b, m=300 GeV, mh=125 GeV ( Jet cone algo. R = 0.5 ) L=2x1033 cm-2 s-1

||, Rb-jet < 1.2, < 0.1 < 2, < 0.1 <1.2, <0.3

No tracking correction

With tracking correction

May 1-3, LHC 2003 V. Daniel Elvira 20

DC04: Calib. & bkgnd.Data Challenge 2004 (DC04): test data reconstruction chain, validate Monte Carlo, optimize detector parameters, develop particle algorithms & calibration tecniques, and perform physics prospect studies.

(a) Calibration & background Samples:• + jet for jet calibration

• W (W -> l ) + N Jets – Standard one e/ background process (N=1,2,3,4) +

• Top quark pair production: tt -> llbb

- higher W pT, jets, • QCD dijet background

Data Format: a Root Tree will be created from DST files

TE

TE

May 1-3, LHC 2003 V. Daniel Elvira 21

DC04: Physics(b) Physics Samples:

• Higgs Production– qq H ( H lljj ) for optimization of HF and TB studies, forward jet tagging,

• WLWL WLWL scattering

- qq WWqq WWqq ljjjj strong dynamics for EW symmetry breaking, jets, , CompHEP-PYTHIA comparisons

• Z´ search– qq Z´ qq (useful for energy resolution studies)

• SUSY particle search– gluino/squark energetic central jet, large

TE

TE

TE

May 1-3, LHC 2003 V. Daniel Elvira 22

• HB and HE hadronic calorimeters completed and assembled. HF fibre insertion finished by the end of 2003

•Goals for the HCal 2002 test beam experiment have been met, moving on to TB03 program

• Looking forward to M.C. production & DC04 for simulation and reconstruction validation, detector optimisation, physics prospects

Summary