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High Energy Physics at TIFR Started with Bhabha and ………. Tariq Aziz TIFR, Mumbai May 27-28, 09 Department of High Energy Physics 14 Faculty + 14 Students + 4 PostDoc 44 Eng + 25 Techs +15 Services + 4 Admin Accelerator Based CMS at CERN, Belle at KEK, D0 at Fermilab D0n Non-Accelerator based Gravitation (Gauribidanur), Cold-atoms (Mumbai) Neutrino physics (PUSHEP) 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 BARC and Delhi University - Silicon Pre-shower Detector. Discriminate between π0/ to detect Higgs 2γ mode (for light Higgs favored by existing data) 2 mm strip width sensor Outer Hadron Calorimeter of CMS Extend HCAL outside the solenoid magnet and make additional shower sampling CMS Detector ¼ Logitudinal view HO HB HF TIFR Colloquium HE Relevant for the late development of showers Lowering of YB-1 and YB-2 TIFR Colloquium 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. Physics potentials of CMS Detector at LHC Test the Standard (model) first and ensure no surprises from the detector before the real surprises from new physics A.K.Nayak, T.Aziz, A. Nikitenko b-Tagging Crucial Purity of b-tagging: IP3D Significance of 3rd track B-discriminator B-discriminator > 2.5>2.5 Efficiency < 40% IP3D Significance of 3rd track Efficiency< 40% Expected measurement for 100 pb-11 Evaluation of b-jet energy correction from data A.K.Nayak, T.Aziz, A.Nikitenko Needed for Higgs, SUSY bbA; A and CPV Higgs Search Resolution is improved by 25 % Jets from Calo Towers Mass peak restored after b-jet corrections From 10 fb-1 of data Measurement of Z e S.Bansal +K.Mazumdar Visible mass in 100 pb-1 Benchmark process for Higgs searches in H emode. e + channel is clean and will be free from severe systematics inherent for jets, specially during initial phase of LHC. signal 520 event, bkg=20 Will be used for normalising l +jet rates. e + combination reduces Drell-Yan background and increases signal rate. invariant mass: assume collinear s poor statistics since e, should not be back-to-back affects mass resolution. Trileptons from Chargino-Neutralino pair ( • K.Mazumdar+ others 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: 3-body decay: Minvmax= m20-m10 2-body decay: M2invmax= (m220-m2~l)(m2~l-m210)/m2~l Accuracy of kinematical end point (~m1/2) about 10 GeV Trileptons from pair can be seen with significance >5 , for m1/2 <250 GeV, with Lint >=30 fb-1 Cosmic rays at CMS TTtttt at Very high momentum – Never done before Muon Charge Ratio A.Nayak, T.Aziz, P.G.Abia Charge ratio Zenith Angle in Radian Indian Participation in BELLE Experiment at KEKB 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 Indian groups: Tata Institute, Mumbai, IMSC & IIT Chennai, Panjab University, IIT, Guwahati (recent) Participation: modest Data Taking, Detector Monitoring and Calibration, Reconstruction Algorithms, Physics Analysis R&D for next Detector phase Determination of RD DCSD/CFD N.Joshi, T.Aziz, K.Trabelsi Estimate internal W-exchange Ds from , K*K, KsK and Ds* from Ds 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 Indian Effort: Mask Design at TIFR, Processing at BEL 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 All on 4-inch n-type bulk wafer TIFR Effort on Silicon Microstrip Detector Design, Simulation and Testing in Institute Lab Fabrication at Bharat Electronics, Bangalore On 300 m thin n-type silicon wafer of 4-inch diameter Developed Single Sided Detector Small Corner Under High Magnification 11 Sets of 32 strips each Strip width Strip pitch Strip length 12 m to 48 m 65 m to 120 m 7.5cm Strip p-type implant AC coupled via Aluminum Overhang - isolated by SiO2 For the first time truly Microstrip Detector developed in India Polyresistors 3-4 M For Common bias DC pad and AC pad on each strip I – V Characteristics I - V Characteristics of Silicon Microstrip Detector Current ( nano amps ) 600 Set 1 Set 2 400 Set 3 Set 4 Set 5 Set 6 Set 7 Set 8 Set 9 200 Set 10 Set 11 0 0 50 100 150 200 250 Voltage ( -ve ) All 11 sets pass acceptance test 300 350 400 450 C – V Characteristics C - V Characteristics 250 Capacitance ( pf ) 200 Set 1 Set 2 Set 3 Set 4 150 Set 5 Set 6 Set 7 Set 8 100 Set 9 Set 10 Set 11 50 0 0 20 40 60 Voltage ( -ve ) 80 100 120 Double sided silicon detector Specifications continued 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 Nex Step: 1024 strips I - V characteristics of Single Sided Detector Current ( nano amps ) 5000 4000 3000 8004-5* 8018-1* 8018-2* 8018-3 8004-7 8004-8 2000 1000 0 0 100 200 300 400 Reverse voltage ( volts ) 500 < 1 nam per strip at 100 volts 1024 Strips C - V characteristics of Single Sided Detector 120 8004-5* 8018-3 capacitance ( pf ) 110 8018-1* 8004-7 8018-2* 8004-8 100 90 80 70 60 50 40 0 50 100 Reverse voltage (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 150 DSSD- N-type strips DC pad N-strip P-stop 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, required for high resolution tracking 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