Richard Jacobsson, CERN The LHCb experiment Brazil USA Poland Finland Ukraine France UK Germany Switzerland Italy Netherlands PRC Romania Russia Spain Richard Jacobsson, CERN

Richard Jacobsson, CERN Outline Physics motivation LHCb at LHC The LHCb detector Front-End electronics Timing and Fast Control (TFC) DAQ Conclusions Richard Jacobsson, CERN

Richard Jacobsson, CERN Physics motivation 1 Ultimate questions: Matter - Anti-matter imbalance in the Universe CP violation a la Standard Model not sufficient Least tested aspect of the Standard Model Flavor physics : More accurate Standard Model measurements in this sector (some parameters known with an accuracy level of only O(30%) Flavor Changing Neutral Currents? (Not in SM) New physics beyond the Standard Model More CP violation Richard Jacobsson, CERN

Physics motivation 2 u c t d s b Yukawa couplings involve quarks from different generations ==> eigenstates of the weak interaction not the same as the mass eigenstates = V Lcc = 2-1/2g (u, c, t)L gm V W+m + h.c. d s b d’ s’ b’ Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb VCKM = W- That is b c Kobayashi and Masukawa 1973 VCKM not diagonal. The structure of the charged current coupling is u c t d s b t b c s u Richard Jacobsson, CERN

Richard Jacobsson, CERN Physics motivation 3 In addition, introducing complex phase into the three-generation mass matrix generates CP and T violation in weak interaction---> (too) small in SM ==> So far, only observed in K mesons (1964) Supersymmetry, left-right symmetric model, leptoquark, …all extensions have strong influence. AIM: Measure flavor parameters as accurately as possible Ex: Unitarity conditions (V+CKMVCKM = 1) Wolfenstein parametrization: VudVub + VcdVcb + VtdVtb = 0 1-l2/2 l Al3(r-ih) -l 1-l2/2 Al2 Al3(1-r-ih) -Al2 1 VCKM ~ Re a b g (1-l2/2)V*ub/(l|Vcb|) r(1-l2/2) Vtd/(l|Vcb|) Im Richard Jacobsson, CERN

Richard Jacobsson, CERN Physics motivation 4 |Vcb|, |Vub|, |Vtd| ==> r and h ==> calculate a, b, g Also measure directly a, b, g from CP asymmetries: b + g from B0d p+p- (background B0d K+p-) b from B0d J/y Ks g from B0d D0K*0, D0K *0 ,D01K*0 B0d - B0d and B0s - B0s oscillations Rare b-decays Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb LHC is the most intensive source of Bu, Bd, Bs and Bc and b-baryons 1012 b-pairs per year (75 kHz) Branching ratios of interesting channel 10-5 - 10-4 5 Hz interesting events LHCb emphasis: B decay reconstruction Particle identification (K/p: ~1GeV/c < p < 150GeV/c) Trigger efficient for both leptonic and hadronic final states. (ATLAS and CMS: no real particle ID and only with lepton triggers Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb detector 1 Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb detector 2 Spectrometer: A single-arm spectrometer covering qmin = ~15 mrad (beam pipe and radiation) to qmin = ~300 mrad (cost optimisation) i.e. h = ~1.88 to ~4.89 has an equal bb acceptance as a large central detector. Locally tunable luminosity Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb Detector 3 Calorimeters Tracker Coil Yoke Shielding plate RICH-1 ~20m Muons Vertex RICH-2 Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb Trigger (L0) High PT leptons photons hadrons muons Pile-up veto Level-0 decision unit 40 MHz crossing rate 1 MHz accept rate Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb trigger (L1) Purpose Select events with detached secondary vertices Algorithm Based on special geometry of vertex detector (r-stations, -stations) Several steps track reconstruction in 2 dimensions (r-z) determination of primary vertex search for tracks with large impact parameter relative to primary vertex full 3 dimensional reconstruction of those tracks Technical Problems: 1 MHz input rate, ~4 GB/s data rate, small event fragments, latency restrictions CN SN y CN Computing Node SN Source Node Richard Jacobsson, CERN

Sub-Farm Controllers (SFC) LHCb Read-out LHC-B Detector Data rates VDET TRACK ECAL HCAL MUON RICH 40 MHz Level 0 Trigger 40 TB/s 1 MHz Level-0 Front-End Electronics Level-1 Timing & Fast Control L0 Fixed latency 4.0 ms 1 TB/s 40 kHz L1 Level 1 Trigger 1 MHz LAN Front-End Multiplexers (FEM) Front End Links 6 GB/s Variable latency <1 ms RU RU RU Read-out units (RU) Throttle Read-out Network (RN) 6 GB/s SFC SFC Sub-Farm Controllers (SFC) Variable latency L2 ~10 ms L3 ~200 ms Control & Monitoring Storage 50 MB/s Trigger Level 2 & 3 Event Filter CPU CPU CPU CPU Richard Jacobsson, CERN

Front-End electronics Richard Jacobsson, CERN

Richard Jacobsson, CERN CERN TTC system 1 Developed in the CERN RD12 project: Timing, Trigger and Control distribution system Used by all LHC experiments Transmitting two channels multiplexed Low latency 40 MHz Encoded long and short broadcasts Richard Jacobsson, CERN

Richard Jacobsson, CERN CERN TTC system 2 LHC: Distribute LHC clock (40.08 MHz) and LHC orbit signal (11.246 kHz) to experiments over fiber with minimal jitter (~8ps RMS) Experiments: Distribute clock, trigger and control commands to the detectors over fiber with minimal jitter Prevessin Control Room Experimental hall Richard Jacobsson, CERN

Timing and Fast Control 1 Richard Jacobsson, CERN

Timing and Fast Control 2 Experiment orchestra director Readout Supervisor Clock, trigger and command distribution and support partitioning TFC switch Throttle feed-back Throttle Ors and Throttle switches (L0 & L1) Richard Jacobsson, CERN

Timing and Fast Control 3 - Trigger controller Trigger controller Throttles - ECS interface ECS interface ECS L0 - L0 distribution (TTC) L1 - L1 distribution (TTC) - Clock distribution(TTC) TTC encoder Ch A/B LHC clock Readout Supervisor: - Module - Auto-trigger generator Trigger generator - Reset/cmd generator Reset/command generator - “RS Front-End” RS Front-End L0/L1 DAQ Richard Jacobsson, CERN

Timing and Fast Control 4 Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb DAQ 1 Readout Units (RUs)/Front-End Multiplexers (FEM) Multiplex input links (Slink) onto Readout Network links (RU) or Slink (FEM) Merge input fragments to one output fragment Destination assignment for Readout Network Readout Network provide connectivity between RUs and SFCs for event-building provide necessary bandwidth (6 GB/sec sustained) Subfarm Controllers (SFCs) assemble event fragments arriving from RUs to complete events and send them to one of the CPUs connected dynamic load balancing among the CPUs connected CPU farm execute the high level trigger algorithms execute reconstruction algorithm Processing needs: ~100 kSI95, i.e. ~1000 processors Note: There is no central event manager Read-out Network (RN) RU 6 GB/s 50 MB/s Variable latency L2 ~10 ms L3 ~200 ms Control & Monitoring LAN Read-out units (RU) Timing Fast Front End Links Trigger Level 2 & 3 Event Filter SFC CPU Sub-Farm Controllers (SFC) Storage Throttle Front-End Multiplexers (FEM) Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb DAQ 2 - RU Two alternative approaches to Readout Unit/FE Multiplexer 1. Customized hardware Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb DAQ 3 - RU 2. Software driven Readout Unit on IBM network processor The IBM NP4GS3 is a network processor designed for wire-speed switching/routing and frame manipulation It can handle over 4.5 Million packets per second on 4 1-Gigabit full duplex links It is fully software programmable Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb DAQ 4 - RU Readout Unit implementation DAQ RU IBM NP4GS3 Phy RN CC - PC PCI Ethernet ECS Mem GbE FEM GMII Switch Bus DASL Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb DAQ 5 - FEM Front-End Multiplexer implementation Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb DAQ 6 - SubFarm Sub Farm Architecture Richard Jacobsson, CERN

Richard Jacobsson, CERN Conclusions Exciting years ahead with design and flavor physics Two TDRs submitted (September 2000) Calorimeters RICHes Building the LHCb readout system is progressing well DAQ TDR end of the year, a lot of work ahead Timing and Fast Control Richard Jacobsson, CERN

Richard Jacobsson, CERN

Richard Jacobsson, CERN LHCb RICHes RICH1: 5cm aerogel n = 1.03, 2-11 GeV 4 m3 C4F10 n = 1.0014, 10-70 GeV RICH2: 100 m3 CF4 n = 1.0005, 17-150 GeV HPD Richard Jacobsson, CERN