High Energy Physics at TIFR

Tariq Aziz

TIFR, Mumbai May 27-28, 09

Started with Bhabha

and ……….

Department of High Energy Physics

14 Faculty + 14 Students + 4 PostDoc

44 Eng + 25 Techs +15 Services + 4 Admin

Accelerator Based

D0n

CMS at CERN, Belle at KEK, D0 at Fermilab

Gravitation (Gauribidanur), Cold-atoms (Mumbai)Neutrino physics (PUSHEP)

Non-Accelerator based

Cosmic rays(Ooty), Gamma-ray astronomy (Pachmarhi & Hanle)

India at LHC

First Large Scale Indian Participation in an InternationalExperiment

Indian accelerator research labs, led by RRCAT, Indore, and BARC, Mumbai, have contributed substantially, in kind, towardsthe LHC machine

Indian scientists/software personnel are contributing in-kind to the development of GRID software

Two groups: India-CMS & India-ALICE

Indian Participation in CMS Collaboration

TIFR and Panjab University

Hardware responsibilities: - Outer hadron calorimeter Ensure more hermetic calorimeter for missing energy

- Silicon Pre-shower Detector. Discriminate between π0/ to detect Higgs 2γ mode (for light Higgs favored by existing data)

BARC and Delhi University

2 mm strip width sensor

TIFR Colloquium

HB

HEHF

HO

Relevant for the late development of showers

CMS Detector ¼ Logitudinal view

Outer Hadron Calorimeter of CMS

Extend HCAL outside the solenoid magnet and make additional shower sampling

TIFR Colloquium

Lowering of YB-1 and YB-2

HO basic design

• Detector element is a plastic scintillator tile which produces light when charged particles pass through it

• This light is collected by embedded WLS fibers

• Light is transported to HPD detector via clear optical fibers spliced to WLS fibers

• Size and placement of the tiles is matched to geometric towers in the Barrel calorimeter

• Tiles are grouped together and packed in “trays” for ease of handling, and 6 trays in each phi sector are in turn inserted inside aluminum honeycomb housings.

Test the Standard (model) first and ensureno surprises from the detector before the real surprises from new physics

Physics potentials of CMS Detector at LHC

b-Tagging Crucial

B-discriminator > 2.5IP3D Significance of 3rd track

Efficiency< 40%

A.K.Nayak, T.Aziz, A. Nikitenko

Purity of b-tagging: IP3D Significance of 3rd track

B-discriminator >2.5Efficiency < 40%

Expected measurement for 100 pb-11

Needed for Higgs, SUSY bbA; A and CPV Higgs Search

Mass peak restored after b-jet corrections

A.K.Nayak, T.Aziz,

A.Nikitenko

Jets from Calo Towers

Resolution is Resolution is improved by 25 %improved by 25 %

Evaluation of b-jet energy correction from data

From 10 fb-1 of data

Measurement of Z

eBenchmark process for Higgs searches in H emode.

e + channelis clean and will be free from severe systematics inherent for jets, specially during initial phase of LHC.

Will be used for normalising l +jet rates.

e + combination reduces Drell-Yan background and increases signal rate.

Visible mass in 100 pb-1

invariant mass: assume collinear s poor statistics since e, should not be back-to-back affects mass resolution.

signal 520 event, bkg=20

S.Bansal +K.Mazumdar

Trileptons from Chargino-Neutralino pair (

• Very low rate, but clean signal in exclusive mode: 3 isolated leptons with 2

OSSF + no hadronic activity in central region of detector extended

coverage of calorimeter needed. Need to resort to mSUGRA model

• 2 possibilities for signal signatures, depending on parameter values:

M2invmax

= (m220

-m2~l)(m2

~l-m2

10)/m2

~l

Minvmax

= m20-m10

Trileptons from pair can be seen with significance >5 , for m1/2 <250 GeV, with Lint >=30 fb-1Accuracy of kinematical end

point (~m1/2) about 10 GeV

2-body decay:

3-body decay:

K.Mazumdar+ others

TTtttt

Charge ratio

Zenith Angle in Radian

Cosmic rays at CMS Muon Charge Ratio at Very high momentum – Never done before

A.Nayak, T.Aziz, P.G.Abia

Indian Participation in BELLE Experiment at KEKB

Indian groups: Tata Institute, Mumbai, Panjab University, IMSC & IIT Chennai, IIT, Guwahati (recent)

Participation: modest Data Taking, Detector Monitoring and Calibration, Reconstruction Algorithms, Physics Analysis

R&D for next Detector phase

BELLE Experiment:A worldwide Collaboration of 400 participants from 55 Institutions

Study the difference between particle and its anti-particle using huge number of B and anti-B mesons And search for Rare B decays

Estimate internalW-exchange

Ds from , K*K, KsK and Ds* from Ds

N.Joshi, T.Aziz, K.Trabelsi

Determination of RD

DCSD/CFD

Silicon Microstrip Detector Development R&D

For BELLE Detector Upgrade in the High Luminosity Phase

Also Develop inhouse capabilities for future participation where High Resolution Tracking is Involved -- SLHC, FAIR , ILC….

Challenging High Tech Area

High Spatial Resolution Tracking DetectorNever Built Earlier in India

Industry Participation – Very Important

Phase I -- Single SidedPhase II -- Double Sided

Single Sided - 11 Sets of 32 strips with different strip width and pitch

Single Sided – 1024 strips with fixed strip width and pitch

Double-Sided with single metal contact

Double-Sided with double metal contact

Wafers with different crystal orientations

Indian Effort: Mask Design at TIFR, Processing at BEL

All on 4-inch n-type bulk wafer

On 300 m thin n-type silicon wafer of 4-inch diameter

Developed Single Sided Detector

11 Sets of 32 strips each

Strip width 12 m to 48 mStrip pitch 65 m to 120 mStrip length 7.5cm

Strip p-type implantAC coupled via Aluminum Overhang - isolated by SiO2

TIFR Effort on Silicon Microstrip Detector

Polyresistors 3-4 M For Common bias DC pad and AC pad on

each strip

Small Corner Under High Magnification

Design, Simulation and Testing in Institute LabFabrication at Bharat Electronics, Bangalore

For the first time truly Microstrip Detector developed in India

I - V Characteristics of Silicon Microstrip Detector

0

200

400

600

0 50 100 150 200 250 300 350 400 450

Voltage ( -ve )

Cu

rre

nt

( n

an

o a

mp

s )

Set 1

Set 2

Set 3

Set 4

Set 5

Set 6

Set 7

Set 8

Set 9

Set 10

Set 11

I – V Characteristics

All 11 sets pass acceptance test

C - V Characteristics

0

50

100

150

200

250

0 20 40 60 80 100 120

Voltage ( -ve )

Cap

acit

an

ce (

pf

)

Set 1

Set 2

Set 3

Set 4

Set 5

Set 6

Set 7

Set 8

Set 9

Set 10

Set 11

C – V Characteristics

Wafer crystal orientation : < 100 >,Type: FZ

Wafer thickness : 300 µm , Size : 4 inch

Resistivity : > 5 Kohm-cm

Breakdown voltage : > 300V

Polysilicon resistor value : > 4 Megaohms

Total Dark current : <= 2 microamps @ 100V

Number of Dead Strips < 1%

Area : 79600 x 28400

Effective Area : 76800 x 25600

Detectors Produced : 1) SSD - 5 No’s

2) DSSD – SL - 10 No’s

3) DSSD – DL - 10 No’s

Double sided silicon detector Specifications continued

Nex Step: 1024 strips

< 1 nam per strip at 100 volts

We had difficulty with pin-holes. That problem is solved

Number of bad strips < 0.5% Similar to Hammatsu

CMS acceptance < 1% bad strip

1024 Strips

N-strip P-stop

Pol

yDC pad

DSSD- N-type strips

Silicon Microstrip Detector design and development,1024 strips on one plane, 512 on the other plane of 300m thin silicon wafer, strip width 12m, length 7600m, common bias via polyresistors, requiredfor high resolution tracking

a tiny corner o

f silic

on

detector

N-type strip width 12µm

Non-Accelerator based Particle Physics

Important Cosmic Ray Research

Areas

• Study of the elemental and isotopic composition of cosmic rays at GeV-TeV energies using balloon or satellite-borne detectors.

• Gamma ray astronomy over the GeV-TeV-PeV-EeV energies.

• Energy spectrum and composition around the knee (E ~ 3 x 1015 eV).

• Energy spectrum and composition around the ankle (E ~ 3 x 1018 eV).

• Energy spectrum and composition at energies ~ 1020 eV and observation of the Greisen-Zatsepin-Kuzmin cutoff.

Air Cherenkov Telescope – 1st of 6

Hanle, Ladakh , 4250 m Altitude

GRAPES-3 Air Shower Array at Ooty )

Most of the Detector Components produced in-house

High quality Scintillators produced at CRL Ooty

Four muon halls, each housing a 4-module

block

CRL Ooty

Forbush Decrease associated with the large Solar

flare of 2003 Oct 28, observed with the GR-3

muon detector

October-November, 2003

Thank You