High Energy Physics at TIFR Tariq Aziz TIFR, MumbaiMay 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 International Experiment Indian accelerator research labs, led by RRCAT, Indore, and BARC, Mumbai, have contributed substantially, in kind, towards the 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 π 0 /  to detect Higgs  2γ mode (for light Higgs favored by existing data) BARC and Delhi University 2 mm strip width sensor

TIFR Colloquium HB HE HF 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 ensure no surprises from the detector before the real surprises from new physics Physics potentials of CMS Detector at LHC

b-Tagging Crucial B-discriminator > 2.5 IP3D Significance of 3 rd track Efficiency< 40% A.K.Nayak, T.Aziz, A. Nikitenko Purity of b-tagging: IP3D Significance of 3rd track B-discriminator >2.5 Efficiency < 40% Expected measurement for 100 pb -1 1

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 improved by 25 % Evaluation of b-jet energy correction from data From 10 fb -1 of data

Measurement of Z     e  Benchmark process for Higgs searches in H     e  mode. e +  channel  is 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: M 2 inv max = (m 2  20 -m 2 ~l )(m 2 ~l -m 2  10 )/m 2 ~l Minv max = m  20 -m  10 Trileptons from  pair can be seen with significance >5, for m1/2 =30 fb -1 Accuracy 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 internal W-exchange D s from , K*K, K s K and D s * from D s  N.Joshi, T.Aziz, K.Trabelsi Determination of R D 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 Detector Never Built Earlier in India Industry Participation – Very Important Phase I -- Single Sided Phase 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 m Strip pitch 65 m to 120 m Strip length 7.5cm Strip p-type implant AC 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 Lab Fabrication at Bharat Electronics, Bangalore For the first time truly Microstrip Detector developed in India

I – V Characteristics All 11 sets pass acceptance test

C – V Characteristics

Wafer crystal orientation :,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 100V Number of Dead Strips < 1% Area : x Effective Area : x 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 Poly DC pad DSSD- N-type strips Silicon Microstrip Detector design and development, 1024 strips on one plane, 512 on the other plane of 300  m thin silicon wafer, strip width 12  m, length 7600  m, common bias via polyresistors, required for high resolution tracking a tiny corner of silicon 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 eV). Energy spectrum and composition around the ankle (E ~ 3 x eV). Energy spectrum and composition at energies ~ eV and observation of the Greisen-Zatsepin-Kuzmin cutoff.

Air Cherenkov Telescope – 1 st 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