CMS Programme India CERN LHC CMS India-CMS Kajari Mazumdar ( on behalf of India-CMS collaboration) Tata Institute of Fundamental Research Mumbai Plan is to cover briefly relevant hardware, software and physics topics. Additional material in talks by Pant, Shukla, Shivpuri . India-CERN meeting, BARC Feb. 28, 2011
Prologue • Long association with CERN: Emulsion, Bubble chamber, LEP good name and also rapport of Indian scientists • LHC enthusiasts’ (Rubbia, Hoogland, ..) visits India from early 90’s. • Groundwork done by Profs. Malhotra, Ganguly and others. • Indian scientists in LHC experiments from nascent, R&D stage. • First Indian group formally in CMS experiment in1994. LHC programme: more multi-dimensional with participation in accelerator, experiment and grid computing. Under India-CERN umbrella each community functions independently. Projects funded by govt. agencies: Dept. of Atomic Energy (DAE) and Dept. of Science & Tech. (DST).
India-CMS collaboration Today, 6-7 Indian groups in CMS, thriving well. • TIFR, BARC, Delhi U., Panjab U., Visva-Bharati U, NISER, SINP About 40-50 physicists, engineers (+ techinical staff ) More teams expected in future • TIFR is the host institute for India-CMS collaboration. • Significant contributions in various fronts, though limited by ‘ distance’ and ‘ time-zone ’ factors. • Hoping for better visibility and support in CMS collaboration in future! • 40 students till now, about 10 finished Ph.D. during last 7-8 years. • More influx of teams, students expected in coming years. Please help us in more faculty recruitment!
Participation of India in CMS experiment till now • Hardware (both in R&D and fabrication in current phase) • Preparatory studies with physics simulation, contributions in LHCC and other milestone documents. Enthusiasm and moral support of Denegri acknowledged. • Software: detector simulation, GEANT specific developments • Test Beam activities for HCAL • Grid computing (Tier2 centre) • Analysis of real data => contribution in publications --- Cosmic muons recorded in CMS --- Collision data (both p-p and Pb-Pb) • Representing CMS collaboration in international fora.
Participation in CMS in future • Detector upgrades, related simulations • Sub-detector related R&D, participation in test-beam activities. • Studies for physics potential for brighter scenarios of LHC • More involvement in remote simulation and analysis • Participation in various responsibilities of CMS (to be enhanced) • Remote Operations Centre for the Asian zone requested • Partial support for students for longer stay at CERN requested Open to ideas for other possibilities as well.
Present hardware participation in CMS 1. Outer Hadron Calorimeter (HO) : TIFR+ Panjab University reduce energy leakage from HCAL: additional depth -->hermetic detector improves resolution for measurement of missing transverse energy, key observable to discoveries Scintillator with HPD/SiPM as light readout 432 Plastic scintillator trays (4-6 units) covering ~ 400 sq. m – 2160 readout channels – 72 honeycomb panel housings (size 2.5 m X 2.0 m) 2. Si Pre-Shower Detector (PSD) in EM CAL endcap ( talk by R.K.Shivpuri) BARC (+ BEL) + Delhi Univ. 3. Resistive Plate Chamber (RPC) (talk by L.M.Pant) BARC + Panjab Univ.
HO detector Pigtail with connector Responsibility: fabrication of scintillator detectors and quality controls. Tile with 4-s groove 5 to 6 tiles in tray. Fibres ganged together to form pigtail, to be connected via clear fibres to photo detector • 6 trays assembled side by side in a HO housing • various Quality • One HO module being installed on a muon ring on Controls at each step. surface (2006) non-trivial coordination with others. eg, MIP signal using cosmic muons. • 3-4 personnel from India at CERN at a given time for Installation, monitoring detector health at every stage.
In the underground pit HO detectors, alongwith muon stations,being lowered down the shaft to underground area • Efficiency of HO detectors during 2010 data taking : about 97% • Calibration of HO using cosmic muons. • Shift duties by Indians • Participation in HO readout upgrade
CMS-HO Calorimeter: present status & near-future activity Issues: • HO elements do not have adequate signal to background ratio for MIPs • HPDs in non-central position have discharging tendency Solution: – Replace HPDs with state of-the-art device SiPM – Provides excellent S/B ratio for muons – Insensitive to ambient magnetic field SiPM characterization facility – Setup for V-I characteristic, single pixel calibration, linearity, MIP studies at Ooty lab. (near Bangalore) Packaging and assembly of bare SiPMs demonstrated at Bharat Electronics Limited (Bangalore)
CMS-HO Upgrade plan: TIFR responsibility Validation of SiPM for CMS environment – Testbeam studies, stability, radiation hardness, magnetic field immunity, saturation effect SiPM Control Boards fabrication • Prototype fabrication carried out in India • Production and quality control of 150 boards in India expected Participation in Installation – Assembly of R/O box, QC and burn-in test at CERN Possibility for fabrication of SiPM at India being probed.
LHC Grid Computing & CMS-T2 centre • One of the 5 CMS Tier2 ( T2-IN-TIFR ) sites in Asia Pacific region operating since last 3 years. Logical parent T1: ASGC, Taiwan • Serving about 60 users from 6 institutes/universities in India • CMS collaboration (>3000 people) uses the facility for coordinated central Monte Carlo event production planned data storage (both collision and simulation) remote analysis of physics data with latest CMS software by any member of CMS collaboration CMS recognizes the performance credit points exchanged against mandatory jobs by collaborators.
Site performance • Resources acc. to pledge: > 500 CPU cores, 600 TB storage can host lots of data to the advantage of whole collaboration, Indian physicists and particularly students. • Availability and reliability of site almost 100% in recent months. (occasional short periods of bad network situation) • Latest versions of software and middleware, regular updates. • Trouble shooting operations taken up fast by support staff. • Data transfers at good rates (typical latency: 10 to 30 min.s). • Good success rate of jobs during last 6 months. With more intense LHC machine performance in coming years expects to serve the community well.
Key to grid computing: network bandwidth • Dedicated P2P link between CERN and India since several years. presently 1Gbps, likely to be upgraded • With requirements of CMS computing (different from ALICE), connection to other T1s achieved (8 more) via peering at CERN end. • Other internet facilities are improving continuously in recent times Significant for site performance, connected to other T2s. • Site taken up for hosting important data streams. • Hubs hosted at TIFR, maintained jointly by CDAC + TIFR. Presently other centres / institutes connected to outside world via TIFR • With NKN connections fully operational in the country in near future, site expected to play bigger role for LHC data analysis by collaborating institutes. (talk on Grid by Apte) Future possibility to use for other purposes (medical, weather, outreach,.)
Some numbers for the period of Jan. to Dec. 2010 • Total amount of data transfers: 350 TB upload, 313 TB download Much more traffic expected from this years onwards • Total number of jobs at site: 674971 (tests + simulation + analysis) • Successful simulation event production jobs : 46510 Average cpu time for 1 p-p collision event simulation ~2.5 s • Successful event analysis jobs: 76701 Submitted jobs rate in 2010 Processed events, cumulative, in 2010 1.7e9 12K
Physics effort from at India • simulation studies, analysis done mostly from India (+short stays @CERN) . • during last several years using grid. • regular presentations of updates remotely over the network. • active discussions among CMS physicists, theorists. Participation in pre-collision era: 1. Physics simulation studies to estimate CMS potential SUSY in trilepton mode invisible Higgs in vector boson fusion process, Z e , as benchmark for e , Zbb process Search for charged higgs several topics with heavy quarks, etc. 2. Test beam: study of detector response, validation of GEANT4 physics of hadronic interactions. 4. calibration of HO subdetector modules 5. Trigger studies
Analysis of Cosmic ray events ( while waiting for collision ) • about 1 billion events collected in CMS detector during 2008. • efficiently used for commissioning of CMS experiment in multiple ways. angular dependence of muons data-driven method for L1 muon trigger efficiency in different regions (S.Bansal, published in JINST) Z × Φ map for RPC efficiency using Tag&Probe method
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