csc update – my random summary

UCLA group meeting 1/9

CSC update – my random summaryCSC update – my random summary

• Another good week for LHC: L=0.9E32 reached (nearly the goal of 1E32 in 2010) Test run with 50 ns bunch spacing “soon”? Possibilities up to 3.5E33 (!) and 4.2 fb-1(!) in 2011. Running could be extended into 2012

• See the following for discovery of Higgs background


4-mu event!4-mu event!

• Masses and lack of other activity are consistent with a Z0Z0 +- +- event

• This is the main background to the high-mass Higgs search

• Went unnoticed by “exciting event selection” tools for 2 weeks, ahem


CSC – other good newsCSC – other good news

CSC efficiencies verified to be significantly higher in DT-CSC overlap region after technical stop fixes

muon L1 pre- and post-firing shown to be at ~1% level in DTs and few per mill in CSC (e.g. Chris study)

Neutrons start to show up in data (see Greg talk)

CEOs plus daily CSC validations shifts appear sufficient


CSC update – issues ICSC update – issues I

• Muon slow particle trigger idea presented Nobody in GMT group can write firmware for it anymore Calorimeter slow particle group is somewhat interested

• Neutron run taken at L~2E31• Clear evidence of extra hits seen in TMB counter rates• Would like to see the actual rates, neutron cross-sections per

chamber type

• CFEB muonic timing Width of the distribution not obviously narrowed… to be

investigated


CSC update – issues IICSC update – issues II

• 2ns tweaks can improve ALCT timing substantially:

From Chris’ talk to L1 trigger DPG 23-Sept-2010


CSC update – issues IIICSC update – issues III

• TMB 3.3v supply droop below 3.135v spec• Is it corroding fuses?

• Investigating TMBs taken from collision hall, gold-plated fuses (tomorrow Greg, Misha)

• CERN does elemental analysis with electron microscope (EDS, 1 week)

• Is it corroding CRB-backplane connections?• Full characterization of ~75 drooping TMBs by Clare

by Weds. Ops meeting?


CSC update – issues IVCSC update – issues IV

• CSC efficiencies: not a very clear picture• Certainly much better than before Technical Stop• Hardware (CSC-TF) has seen many changes, so

keep it unchanged for the rest of this year• Numerous conflicting analyses - suggest to:

• Define a sample of well-identified but unbiased muons as denominator

• Break down by every trigger & offline selection level• Show eta-phi plot of losses• Have high statistics• Must compare to correct Monte Carlo simulation

version to understand properly• Algorithms were always tuned so MC performs well!


CSC update – issues VCSC update – issues V

• High luminosity (3.5E32?) and 50ns bunch spacing issues

• Wide readout windows again lead to missing (CLCT) or duplicate (CFEB, ALCT) CSC data

• Any other issues? Anyone?

• CSC daily monitoring shifts need streamlining

• The work seems to have begun


CSC update – issues VICSC update – issues VI

• Overall CSC group structure• Probably heading towards Ops, DPG, and Upgrade

deputies by ~December

• CSC Detector Performance Group (DPG)• Muon DT has proposed fully merging CSC, DT, and

RPC groups• Not much enthusiasm by CSC collaborators

• Current meetings work pretty well, ~40 people

• Establish the sub-structure?• Good to organize high-priority activities• Good to know who to ask about specific issues• Bad if people feel locked into the structure


Stuff mentioned beforeStuff mentioned before

• Don’t need to go through these again today


CSC nagging concerns ICSC nagging concerns I

• Changes to data structure• ALCT timing information from Chris DIGIs?• Mini-scope etc. in TMB• Allowed now for future CMSSW version 3.9 ??

• Improved documentation• General muon DPG detector performance article?

Might naturally break into 3 papers, but preferably not.

• CSC synchronization article• Twikis, especially on timing, online changes• Storage and tracking of firmware versions ALCT,

TMB, CCB, MPC, DDU, DCC, CSCTF, VCC, etc.


CSC nagging concerns IICSC nagging concerns II

• Triggers & datasets: where do all of these go?

• Single high-Pt triggers and datasets• Onia triggers and datasets• Single low-Pt (e.g. b physics) triggers and datasets• Halo muons• CSC activity triggers

• Everyone sees a “piece” of the puzzle…• Would like to assemble known information…

• Are we missing anything?• Need to improve DIGI information on timing, e.g. CSC

anode timing?


CSC upgradeCSC upgrade

• Technical Proposal muon section in decent shape, maybe more verbiage on physics justification

• David S. and Taylor to work on actual justification during Fall

• Upgrade ME4/2:• Panels via CERN – try for sole-source procurement• ME4/2 electronics – make at least one endcap of

CFEBs to decouple schedule from ME1/1?

csc update – my random summary

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