1. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 1 Trigger Performance & Strategy Working Group Report Oliver Buchmueller Imperial College Wesley H. Smith U. Wisconsin Upgrade Project Office Meeting August 3, 2012 Outline: Discussion with Physics about Physics Priorities for the Trigger upgrade Results from second meeting on Trigger Architecture Note: next meetings: Discussion on Tracking Trigger during Lisbon Week Follow-up on trigger architecture, Tuesday, Sept. 11 2-6 PM

2. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 2 Physics Priorities in 2015+ Present Understanding Need to study the properties of the new particle in detail to answer important questions about its underlying nature. Mass, Spin, Couplings, Production mechanisms and decays. A 125 GeV Higgs-like particle in expected to be very rich in decay and production. Thus it is mandatory to cover all possibilities. This program of work will require keeping the trigger acceptance for Higgs at least as high as in 2012. Doubling the energy to 14 TeV in 2015 will also open the door to a completely new energy regime (i.e. 2 TeV and higher) for our searches. This requires keeping the same sensitivity for SUSY and Exotic searches that we have in 2012. SUSY benchmarks are different, and possibly more challenging Will use benchmarks from Physics to L1 Trigger Phase 1 Upgrade

3. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 3 Required Trigger Menu in 2015+ Present Understanding The trigger menu for 2015+ would have similar acceptance to the 2012 menu The starting point for studies is the 2012 menu and its relative allocations of bandwidth modified to fit within the constraints of a L1 trigger rate of 100 kHz and an HLT output rate of 400 Hz at a luminosity of 2E34 and energy of 14 TeV.

4. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 4 Phase II and Beyond Present Understanding Harder to define a Physics program for this time and a much will depend on the outcome of the 2015+ run campaign. One option would be to adopt a program similar to the linear collider and try to study with high precision the properties of the Higgs (or whatever it reveals itself to be), with a special focus on self-couplings and precision measurements of couplings. This would require (again) to keep the trigger acceptance for Higgs at least as high as in 2012. We also require the same sensitivity for SUSY and Exotic searches that we have in 2012. ⇒ Working Hypothesis: use Phase 1 menu as a starting point

5. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 5 DAQ, Computing, Tracker DAQ assuming 10 MB event size: Readout at 100 kHz, 1 MHz no problem, HLT OK Readout at 40 MHz very difficult, HLT too high cost Output at 10 kHz OK (confirmed w/ F. Meijers) Computing: Assuming factor ×3 in event size & ×3 in reco. time Can accept 10 kHz sustainable data-taking Tracker with 1 MHz L1 and track trigger: Outer architecture doesn’t work New solution needs to be developed e. g. Sparsify L1 data, keeping the same allocated bw Need to check if this would work Not a small change. Implications on FE chip Inner architecture may or may not work L1 bw is larger for same occupancy because of z address, and occupancy is larger in itself Worst case: Shift boundary to higher radius for these modules Need to follow up with tracker on details of above Urgent to have a timely decision on architecture

6. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 6 Input from Calorimeters ECAL: First look at increasing L1 Latency, Rate > 6.4 usec, 100kHz To meet latency/rate specs, need to change: On ‐ detector ECAL digital electronics (FE + optical links) ECAL off ‐ detector electronics (DCC + TCC + CCS + power supplies) Est. Cost: 12 MCHF Cooling system must remain unchanged and untouched Replacement of EB FE + Links would require: Of the order of 10 ‐ 20 MCHF for hardware alone 10 ‐ 15 engineers/physicists/technicians for 4 ‐ 5 years Some of this work may occur anyway if replace EE+ES system Two years of work during a shutdown 25 FTE for two years Non ‐ negligible risks to the existing detector and personnel Currently examining other means of coping with higher latency/rate HCAL: L1A rate of 250 kHz is achievable with presently planned upgrade L1A rate of 1 MHz requires AMC13 replacement with either more 10 Gbps links (need 8... hard) or future 40 Gbps links. (Estimate ~$400k+engineering for all of HCAL) - with 40 GB QSFP (Quad Small Form-factor Pluggable) → would need different FPGAs

7. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 7 Input from Muon Systems to enable L1 > 3 usec, 100 kHz RPC: New RMB (Readout Mezzanine Board) mezzanines (84) New RMB → DCC Optical links (presently 84 u. 640 Mbps GOL) New DCC cards (Presently 3 u. ECAL DCC with modified firmware) Total Cost ~ 100 K€ DT: On-detector ROB HPTDCs accept L1A up to 25 µsec Replacing ROB’s major effort Higher L1A rate or latency requires new ROS Readout Server Boards will be in USC, planned redesign once, “Not very expensive” DDU limit is 250 MB/s (1 kB/evt x 250 kHz L1A) Can probably sustain 500 kHz by doubling f FEDs & reducing debugging trigger data ROS wil be redesigned in USC either way, if L1A rate increases, ROS may become DDU ROS to DAQ directly=> review how many extra DAQ connections will be needed: no limit means 36 “Slinks” (10 Gbps) instead of present 5-10 CSC: CFEB SCA bottleneck 3.2 µsec L1A latency + CLCT rate (poisson statistics) 26 µsec digitization + L1A rate (queue statistics) DCFEB not restricted Only planned for ME1/1 – cost for all CSCs = 12 M$ Limited to < 800 kHz L1A unless replace DDU – not planned at moment

8. O. Buchmueller, Imperial College, W. Smith, U. Wisconsin, August 3, 2012 Trigger Performance and Strategy Working Group Trigger Performance and Strategy Working Group - 8 Conclusions on Architecture The option of a L1 Trigger rate of 1 MHz and HLT output rate of 10 kHz is feasible for all subsystems, DAQ and Computing, but has a significant cost and is under serious consideration. We still need to gather further information from Tracker & ECAL Already much useful information provided! Follow-up meeting Tuesday, Sept. 11 2-6 PM Gather further information, have discussion This option will need much discussion in the UPO and CMS management. This is just a “heads up”