RPC Efficiency Status

1. Camilo Carrillo On behalf of the RPC Group RPC Efficiency Status Workshop RPC Italia Ischia September 20 – 22 2009 Departamento de Física UNIVERSIDAD DE LOS ANDES Bogotá, Colombia

2. Our tools for RPC Efficiency Where to find the results of CRAFT09 Analysis Historical Plots for the efficiency DQM + Storage Plot New Muography Status in the EndCap HV Scan Chambers in Plateau HV Scan Double Vs Single Gap Work to be done and conclusions Outline

3. DT Segment Extrapolation for the Barrel DQMOffline Prompt Analysis Storage Plots (Includes 2D histograms) HLT Module (work is ongoing) Track + Segments (coming soon) CSC Segment Extrapolation for the EndCap DQMOffline Prompt Analysis Storage Plot HLT Module (work is ongoing) Track + Segments (coming soon) Track Extrapolation (Whole system with p-p) Prompt Analysis Our tools for the efficiency

4. Just a reminder for the Segment extrapolation We use residuals to check the quality of the tool used to measure RPC efficiency with segment extrapolation. Y Residual Y RPC RPC Rec Hit DT/ CSC X RPC Local Frame. X Point extrapolated from DT Segment We plan to store this information in the event Residual The idea for the track extrapolation is very similar.

5. Agreement between different tools and validation DT Segment Track By Raffaello

6. CRAFT09 results for efficiency run by run where to find it? • Storage Plot. • https://twiki.cern.ch/twiki/bin/view/CMS/RPClistofRunP5CRAFT09 • Advantages. • Easy correlation with the conditions of the • system HV TH Trigger Rates, B field, etc. • 2D plots • Modifications are independent of CMSSW releases Disadvantages • Is not run automatically in Tier0 (run at CAF) • DQMOffline • https://cmsweb.cern.ch/dqm/offline • Advantages • Automatically produced in Tier-0 • Integration to CMS tools • Easy and automatic history plots Disadvantages • No 2D plots. • Modification attached to CMSSW releases. • Results not corrected yet for masked strips! • But as much as possible has to be moved from Storage Plot to DQMOffline (Work ongoing)

7. From the package in DQMOffline (segment extrapolation) historical plots for the efficiency are automatically produced Still missing histograms with global info about the efficiency work to be done http://cmstac05.cern.ch/historic_dqm/HistoryDQM/AllRuns/Plots_RPCHistoricInfoClient

8. History Plots CRAFT09 Barrel Storage Plot 95% Run #

9. History Plots CRAFT09 EndCap Storage Plot Run #

10. Better Muongraphies w.r.t. CRAFT08 Spacers Corners of the gas gaps Meassurment of the border effect in the efficiency Uniform efficiency in plateau

11. 2D Efficiency for different HV Open problem, pending excersice with event display

12. Distribution of the inefficient extrapolations 9.1kV 9.0kV 9.2kV 9.3kV

13. Comparing Efficiencies for the BarrelCRAFT09 Vs CRAFT08 RPCs are collecting data this year with much better efficiency due to many improvements! CRAFT08 Run 67647 9.3kV 230mV CRAFT09 Run 109578 9.3kV 220mV Swapped Cables were corrected Few Single Gap Chambers Better Synchronization

14. Results about the endcap Extrapolating all the segments Increase of ~5% With the filter asking for correlated segments between different disks Results in DQMOffline Prompt Analysis and Storage Plot don't have this filter

15. HV Scan CRAFT09 Global Picture Barrel EndCap

16. Double Gap Vs Single Gap Example Single Gap Chamber Single Gap Chambers (From Anna C.) W+1 S8 RB3+_UP W0 S6_RB2out_DOWN S1_RB1out_DOWN W-2 RB1out_s12_DOWN Example Double Gap Chamber

17. HV Scan EndCap 220mV

18. CRAFT09 has shown a better performance of the RPC system in terms of efficiency HV Scan was done with success we have the data and the tools to set the working voltage for future data taking Drop in the efficiency due to the presence of spacers is clear Tool to check the uniformity in the efficiency along the chamber is ready New things to implement in DQMOffline Understand the effect of timing in the endcap efficiency Cut in the selection of the segments for the endcap to be implemented Comparison with efficiency from trigger bits Vs CSC segment extrapolation to be done Implementation in the HLT stream of the segment extrapolation (to select pathological events) Analysis of CRAFT09 data is still ongoing Tool Track+Segment to be developed Conclusions and Work to be done

19. Backup Hi all, I think I understand this effect. It has to do with the fact that the CSC trigger was running with a pointing track requirement. It requires the coincidence of 2 or more chambers on different disks, and those segments must pass an eta difference cut, where eta is computed assuming the muon came from the nominal vertex. Now, what makes this strange for cosmics is that the CSC chambers are staggered, i.e. overlapping. This means some chambers are close to the disk, and some farther away by the width of a chamber. Now it turns out the chambers have exactly the same staggering on both sides of the YE2 disk (ME2 and ME3). If one chamber is close to the disk, so is the one behind the disk. The neighbor chambers are both farther away from the disk. Thus the distance in Z separating ME2 and ME3 is maximally varying. Since the CSCTF cuts on the eta difference between segments in two disks, those CSCs that are close together will have a wider acceptance for cosmics (larger angular acceptance relative to cosmics). Probably worth sketching this out, but the range of allowed angles for cosmics to pass the eta difference cut is larger when the Z separation is smaller. The odd-numbered chambers of CSC are the ones with this closer separation, and indeed the CSC DQM plot shows the rate higher for those chambers. But the rate should not be zero for the even numbered chambers, just reduced. So I don't understand why the plot in Gianni's DT presentation seems to suggest NO muons originating from the even numbered chambers. That is not consistent with the CSC and RPC DQM plots posted. Regards, Darin