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Activities in CMS. Presented by Hafeez Hoorani National Cente for Physics Presented in JCPC – May 14, 2012. EHEP Group. Role of EHEP Group. DETECTOR WORK: Maintaining 432 RPC detectors installed at CERN in CMS detector Two persons – Engineer and Physicist are required at CERN
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Activities in CMS Presented by Hafeez Hoorani National Cente for Physics Presented in JCPC – May 14, 2012
EHEP Group H. Hoorani - NCP
Role of EHEP Group • DETECTOR WORK: • Maintaining 432 RPC detectors installed at CERN in CMS detector • Two persons – Engineer and Physicist are required at CERN • Developing readout electronics for RPC upgrade. • PHYSICS ANALYSIS: • Physicists & Students are needed (4 PhD + 8 PhD Students) • Stationed at CERN 2 PhD students, two more will go • GRID NODE: • 524 CPU, 170 TB, 155 Mbps • During the period 01.10.2011 – 31.12.2011: • Data downloaded: 14,000 Gbyte • Number of Jobs processed: 186,539
Physics Analysis • Main focus is Physics of Top Quark (Production & Decay) • One PhD student working on resonances • Areas in Top Quark Physics: • Measurement of σtt in semi-leptonic channel • Measurement of top mass • Direct reconstruction • Using pT jets • Measurement of W helicity in top decays • Decays of single top – measurement of Vtb . • Hiring new faculty member: SUSY searches, Limits for various searches
PγT > 0.5 GeV/c , |yJ/ψ| < 1 , 7.0 GeV/c < pTJ/ψ < 25.0 GeV/c • Other Selection Cuts: • Muon Selection: • Hits in pixel ≥ 2 • Hits in tracker ≥ 11 • Track fit Χ2/ndof< 1.8 • μμ vertex fit probability> 0.01 • pμT, |η| < 1.3 3.3 GeV/c • pμT, 1.3 <|η| < 2.22.9 GeV/c • Muon idTrackerMuonOneStationTight • Photon Conversion Selection: • Electron Track hits ≥ 4 • Electron Track fits Χ2/ndof< 10 • Distance of Approach-2.5cm <dm< 1cm • Signed Impact parameterq.d0 > 0 • e+e- vertex fit probability> 5 × 10-4 • Radius of ConversionRconv > 1.5 cm mμμ < 3.0 – 3.2 GeV/c2 Decay Channel Studied: Χc0,1,2→ J/ψγ 2011 Data: RunA, RunB Integrated Luminosity: 4.62 fb-1 Invariant mass distribution of J/ψ Selection of Candidate lJ/ψ < 30 μm Rejection of pi0: 0.11 GeV/c2< mγγ< .15 GeV/c2 Decay length distribution of J/ψ originating from Χc
Photon Efficiency Measurement: Convolution of the probability of the Photon to convert and Photon conversion reconstruction efficiency combined with the Χcselection cuts. Method to measure σχc2/σχc1 Results of σχc2/σχc1 |ηΥ| < 1 • Systematic uncertainties: • Uncertainty from mass fit and Χc1and Χc2 counting • Uncertainty on ratio of efficiencies • Pileup • Χc polarization • Branching fractions Signal isfittedwith Double-sidedCrystall Ball function. AndBckisfittedwithGenericfunction: Nbkg = (x-q0)α1.e(x-q0)β1
Decay Channel Studied: Χb(3P) → ϒ(1S)γ 2011 Data: RunA, RunB Integrated Luminosity: 4.7 fb-1 • Selection: • Same selection criteria is used for muonand converted photon selection, as we used in case of Χc. • Photon-Υ Vertex Compatibility < 5 σ • InvMass:8.5 GeV/c2< mμμ< 11.5 GeV/c2 Observation of Χb(3P): Results The recently discovered Χb(3P) state at ATLAS is observed with a signal yield of110 ± 19 events, a significance of6.9 σ and a Mass of 10514.9 ± 6.9 ± xx MeV.
Resistive Plate Chamber System CMS Operation Requirements • Efficiency > 95% • Time resolution . 3 ns • Mean cluster size . 2 strips • Rate capability . 1 kHz/cm2 • Operation plateau > 300 V • # Streamers < 10% Double gap gas chambers 1. The RPC subdetector consist of 912 covering |η| < 1.6, for an active area of ~2953 m2. 2. They are characterized by a time resolution 3 ns, and a spatial resolution of ~ 1cm.
Detector Stability Since July 2011 automatic temperature and pressure corrections. Variation of the environmental pressure P and the temperature T inside the CMS cavern used to rescale effective voltage HVeff(P,T) = HV. . T0= 293K P0 = 965 mbar Runs without automatic pressure correction In 2011 proton-proton data, an increased stability, with reduced fluctuations is observed in cluster size and efficiency studies, after the correction is applied. Runs with automatic pressure correction
Working Point Calibration: HV Scan Efficiency Calculation Method • Linear extrapolation of every track segment in DTs and CSCs toward the associated RPC strip plane. • matched to the cluster (a strip or a set of contiguous strips) closest to the extrapolated impact point. This method provides both a measure for the efficiency and, through the residuals, for the spatial resolution.
2011 HV Scan A high voltage scan was performed during early 2011 collision data and recorded at 11 different HV settings during a series of dedicated runs to define the optimal operating voltage for each chamber.
2012 HV Scan • Here the expected efficiency distribution at the 2012 working point • We will check results with data as soon as we apply the new HV setting
Efficiency at WP per disk • Here the same per endcap disk. • RE3 is a little bit larger and with an average of about 93.6%
Radial distribution of the rate Barrel CMS Preliminary 2011 Outermost station Innermost station RPC Background rate as a function of the instantaneous luminosity, for four radial stations of Barrel wheel W-2. Outermost station affected mainly by neutron background, innermost mainly affected by particles coming from the vertex. 17
Radial distribution of the rate EndCap+ CMS Preliminary 2011 RPC Background rate as a function of the instantaneous luminosity. Innermost rings are the most affected.
Radial distribution of the rate EndCap- CMS Preliminary 2011 Negative disks show higher rate with respect to the positive, due to the presence of CASTOR on the negative side of CMS.
Current vs. Luminosity Current distribution shift vs. luminosity for a single Endcap station (Disk-2). Correlation between current and beam intensity evident. Maximum current registered for each Endcap station vs. Luminosity. 8-fold increase luminosity 4uA increase in current
RPC Endcap Status after 2 years Operations • Total installed chambers in Endcap = 432 (864 Gaps) • After successful 2 years of Data (5 fb-1) taking: HV Problems: • 3 Chambers OFF (All in RE±1). • 26 in Single Gap Mode ( 3 % of Endcap Chambers). • 10 SG chambers in RE±1 and 16 SG chambers in RE±2, RE±3. Thresholds/LV Problems: • RPC line not working, no control at all (10 entries). • Misbehaving components (single FEBS with strange readings) (1 entry). • Overall Active Channels are 98.3 %
Over All Performance in 2011 • Data Loss for RPC 19pb-1 = 0.37 % • Overall Operating Channels 98.4% • Average Efficiency 95% • Average Cluster Size < 2 • Average Noise rate(3.1033 cm-2S-1) 1.3Hz/cm2 • Max Noise Rate < 7Hz/cm2 • Average Intrisic rate (no beam) ~0.1Hz/cm2 • Average current (no-beam) ~ 1μA • Average current (with-beam) ~ 1.5μA • Temperature < 22.5 0C
Requirement For 200 RPCs, the Front End Electronics • 600 Front end boards (50 Spares). • 200 Distribution boards (50 Spares). • 1200 Adopter boards with coaxial cables (50 Spares).
Status overview • Front End Boards (FEBs) • Components Ordered (650 boards) • PCBs 50 ready • Stencil ready • Stuffing Done • Distribution Boards (DBs) • Components Ordered (250 boards) • PCBs 50 ready • Stencil ready • Stuffing Done • Adapter Boards(ABs) • Forty chambers Cables with Ferrules Completed • One hundred and sixty (160) chambers cables. In-progress
FEB Status • Front End Boards (FEBs) • 50 FEB are ready and shipped to CERN.
DB Status Distribution Boards (DBs) • 50 DBs tested and shipped to CERN.
DB Testing Setup • We have test and validation system of both FEB and DB board. • Measuring and storing all parameter according to CMS Database. DB testing/Validation Section FEB Testing/Validation Section
Adapter Board & cabling • RE4/* cabling: (Total Cost of Project : 40KCHF) • RE4/3, 40 chambers cables are completed with ferrule. • RE4/2, 20 chambers cables are completed with ferrule.
Database We are providing such types of parameters to maintain the database in CERN
NCP Team • Dr.Hafeez Hoorani • Project Manager/Director Research • Waqar Ahmed • Resource Manager/Senior Engineer • Technical coordination • Saleh Muhammad • Testing of FEB/DB/ Senior Scientific officer • Coaxial cable quality assurance • M.ImranMalikAwan • Quality Assurance of FEB/DB/ Senior Scientific officer • Database • Hassan Shahzad • Coordinator/ Senior Scientific officer
Installed Resources NCP – LCG2 * Recently NCP purchased 110 TB (Raw) of additional disk storage and it will be in production shortly.
28 Server Machines, Sun Fire X4150, 2 x Quad core Intel(R) Xeon(R) CPU X5460 @ 3.16GHz16 GB RAM Number of Physical CPU’s = 56 Number of Logical Cores =224 25 Server Machines Dell Power Edge R610, 2 x Hex core processor Intel(R) Xeon(R) CPU X5670 @ 2.93GHz 24 GB RAM. Number of Physical CPU’s = 50 Number of Logical Cores =300 10 Transtec NAS4324M-A, Intel Xeon E5520 -2x2.26 GHz, 12 GB RAM, 24 SATA Drives provides 23 TB of RAW storage. Total online storage = 170 TB CPUs and STORAGE
Utilization of Resources – Year 2012 Norm. SUM CPU (KSI2K-hours)
Common Problems • Network Connectivity • Higher Education Commission of Pakistan has provided 155 Mbps to NCP, which is far less then minimum required (~1Gbps). • Network disruptions at service provider’s level due to various reasons. • Electric Power • Pakistan hassled dreadfully by the severe power-shortage in recent times. • Extensive load-shedding harmfully impacted the battery backups for power generation. • In summer the temperature of data centre rises due to insufficient cooling. This problem will be cater soon by installing new air-conditioning units.