1 / 26

Momentum scale in the 2012 data in v94: improved MS alignment

Momentum scale in the 2012 data in v94: improved MS alignment. Niels van Eldik, Peter Kluit, Alan Poppleton MCP/MATF meeting 1November 10 October / 20 May 2012. Introduction. Use Z skimmed data periods 2012 v94: Currently used at Tier 0 Standard selection of two CB muons pT > 25 GeV

ayame
Download Presentation

Momentum scale in the 2012 data in v94: improved MS alignment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Momentum scale in the 2012 datain v94: improved MS alignment Niels van Eldik, Peter Kluit, Alan Poppleton MCP/MATF meeting 1November 10 October / 20 May 2012

  2. Introduction Use Z skimmed data periods 2012 v94: Currently used at Tier 0 Standard selection of two CB muons pT > 25 GeV Basic idea: use the Z mass as probe Mass = (Combined parameters, SA parameters) and vice versa Plot dM/Mz = (Mass(eta SA, phi sector MS)-Mz)/Mz dM/Mz -> observe B field effects q*dM/Mz -> sensitive to MS calibration and alignment Extrapolate the q dM/M number to 1 TeV from pT = 40 GeV. So express systematic curvature offset as alpha (typically 0.10): dpT/pT = alpha pT TeV-1 @ 1 TeV Use therefore a factor 2*1000/40 = 50 to go from dM/M to alpha. Reason for factor 2: 2*dM/M = dp/p (M2 = p1*p2 etc)

  3. v94: q*dM/MzID parameters small ID mis alignments

  4. ID parameters v94 Yellow band dpT/pT = +- 0.20 (pT/TeV)

  5. v94: q*dM/MzCB parameters Phi modulation due to ID-MS mis alignment Better than Tier0 processing

  6. CB parameters v94 Yellow band dpT/pT = +- 0.20 (pT/TeV)

  7. v94: q*dM/MzSA parameters Compare to next slide

  8. SA parameters v94

  9. v94: q*dM/MzSA best parameters • Best selection: • No BEE/EEL/EES • - 3 stations • 2 phi layers • no Barrel-Endcap

  10. SA best parameters v94

  11. v94: no q dM/MzID parameters

  12. v94: no q dM/MzCB parameters

  13. Conclusions Relevant for the Higgs are the CB and ID momentum resolutions Observe some misalignments in ID in endcaps both all smaller than dpT/pT < 20% @ 1 TeV Some structure in the CB in the endcap (eta >0). Similar to structure observed in Tier0 processing. Maximally dpT/pT ~20% @ 1 TeV. Note that the structure in the mass (slides 11-12) is much smaller (due to cancellation of + and – charges). Likely cause of structure in (positive eta) endcap is ID-MS misalignment. Means that v94 is better for MS alignment. However, an additional ID-MS alignment is needed to reduce the momentum bias of less than ~20% @ 1 TeV.

  14. Momentum scale in the 2012 datain v93: improved MS alignment Niels van Eldik, Peter Kluit, Alan Poppleton MCP/MATF meeting 1November 10 October / 20 May 2012

  15. Introduction Use Z skimmed data periods 2012 v93 Standard selection of two CB muons pT > 25 GeV Basic idea: use the Z mass as probe Mass = (Combined parameters, SA parameters) and vice versa Plot dM/Mz = (Mass(eta SA, phi sector MS)-Mz)/Mz dM/Mz -> observe B field effects q*dM/Mz -> sensitive to MS calibration and alignment Extrapolate the q dM/M number to 1 TeV from pT = 40 GeV. So express systematic curvature offset as alpha (typically 0.10): dpT/pT = alpha pT TeV-1 @ 1 TeV Use therefore a factor 2*1000/40 = 50 to go from dM/M to alpha. Reason for factor 2: 2*dM/M = dp/p (M2 = p1*p2 etc)

  16. v93: q*dM/MzID parameters small ID mis alignments

  17. ID parameters v93 Yellow band dpT/pT = +- 0.20 (pT/TeV)

  18. v93: q*dM/MzCB parameters Phi modulation due to ID-MS mis alignment Similar to Tier0 processing

  19. CB parameters v93 Yellow band dpT/pT = +- 0.20 (pT/TeV)

  20. v93: q*dM/MzSA parameters Compare to next slide

  21. SA parameters v93

  22. v93: q*dM/MzSA best parameters • Best selection: • No BEE/EEL/EES • - 3 stations • 2 phi layers • no Barrel-Endcap

  23. SA best parameters v93

  24. v93: no q dM/MzID parameters

  25. v93: no q dM/MzCB parameters

  26. Conclusions Relevant for the Higgs are the CB and ID momentum resolutions Observe some misalignments in ID in endcaps both all smaller than dpT/pT < 20% @ 1 TeV Some structure in the CB in the endcap (eta >0). Similar to structure observed in Tier0 processing. Maximally dpT/pT ~20% @ 1 TeV. Note that the structure in the mass (slides 11-12) is much smaller (due to cancellation of + and – charges). Likely cause of structure in (positive eta) endcap is ID-MS misalignment. Means that v93 is better for MS alignment. However, an additional ID-MS alignment is needed to reduce the momentum bias of less than ~20% @ 1 TeV.

More Related