High Energy Physics at TIFR

1. High Energy Physics at TIFR Started with Bhabha and ………. Tariq Aziz TIFR, Mumbai May 27-28, 09

2. 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)

3. 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

4. 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

5. Outer Hadron Calorimeter of CMS Extend HCAL outside the solenoid magnet and make additional shower sampling CMS Detector ¼ Logitudinal view HO HB HE HF Relevant for the late development of showers

6. Lowering of YB-1 and YB-2

7. 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.

8. 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

9. A.K.Nayak, T.Aziz, A. Nikitenko b-Tagging Crucial Purity of b-tagging: IP3D Significance of 3rd track B-discriminator >2.5 Efficiency < 40% B-discriminator > 2.5 IP3D Significance of 3rd track Efficiency< 40% Expected measurement for 100 pb-11

10. A.K.Nayak, T.Aziz, A.Nikitenko Needed for Higgs, SUSY bbA; A and CPV Higgs Search Mass peak restored after b-jet corrections Jets from Calo Towers Evaluation of b-jet energy correction from data Resolution is improved by 25 % From 10 fb-1 of data

11. 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 tl +jet rates. e +  combination reduces Drell-Yan background and increases signal rate. Visible mass in 100 pb-1 signal 520 event, bkg=20 S.Bansal +K.Mazumdar invariant mass: assume collinear s  poor statistics since e,  should not be back-to-back  affects mass resolution.

12. 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: Minvmax= m20-m10 M2invmax= (m220-m2~l)(m2~l-m210)/m2~l Trileptons from pair can be seen with significance >5 , for m1/2 <250 GeV, with Lint >=30 fb-1 Accuracy of kinematical end point (~m1/2) about 10 GeV K.Mazumdar+ others 3-body decay: 2-bodydecay:

13. Cosmic rays at CMS Muon Charge Ratio at Very high momentum – Never done before TTtttt A.Nayak, T.Aziz, P.G.Abia Charge ratio Zenith Angle in Radian

14. 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, 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

15. Determination of RDDCSD/CFD N.Joshi, T.Aziz, K.Trabelsi Estimate internal W-exchange Ds from , K*K, KsK and Ds* from Ds

16. 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

17. 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

18. Small Corner Under High Magnification Polyresistors 3-4 M For Common bias DC pad and AC pad on each strip 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 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 For the first time truly Microstrip Detector developed in India

19. I – V Characteristics All 11 sets pass acceptance test

20. C – V Characteristics

21. 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 Detectors Produced : 1) SSD - 5 No’s 2) DSSD – SL - 10 No’s 3) DSSD – DL - 10 No’s

22. Nex Step: 1024 strips < 1 nam per strip at 100 volts

23. 1024 Strips We had difficulty with pin-holes. That problem is solved Similar to Hammatsu Number of bad strips < 0.5% CMS acceptance < 1% bad strip

24. DSSD- N-type strips P-stop DC pad N-strip N-type strip width 12µm Poly a tiny corner of silicon detector 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

25. Non-Accelerator based Particle Physics

26. 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.

27. Air Cherenkov Telescope – 1st of 6Hanle, Ladakh , 4250 m Altitude

28. GRAPES-3 Air Shower Array at Ooty ) Most of the Detector Components produced in-house High quality Scintillators produced at CRL Ooty

29. Four muon halls, each housing a 4-module block CRL Ooty

30. Forbush Decrease associated with the large Solar flare of 2003 Oct 28, observed with the GR-3 muon detector October-November, 2003

31. Thank You