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Validation of the 5fb -1 Dataset for the Delayed Photon Analyses

Validation of the 5fb -1 Dataset for the Delayed Photon Analyses. Jonathan Asaadi , Adam Aurisano, Daniel Goldin, and David Toback (On behalf of the Delayed Photon Group) Texas A&M University. Outline. Overview/Motivation of Delayed Photon Analysis Data Selection

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Validation of the 5fb -1 Dataset for the Delayed Photon Analyses

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  1. Validation of the 5fb-1 Dataset for the Delayed Photon Analyses Jonathan Asaadi, Adam Aurisano, Daniel Goldin, and David Toback (On behalf of the Delayed Photon Group) Texas A&M University

  2. Outline • Overview/Motivation of Delayed Photon Analysis • Data Selection • Components of the Corrected Time and calibration procedure • Vertex Time • Vertex Z • EMTiming • TOF • Conclusions / Next Steps

  3. Overview of Delayed Photon Analysis In some forms of Gauge Mediated Supersymmetry (SUSY) the next to lightest stable particle (NLSP) is long lived (lifetime on the order of nanoseconds) before decaying to a photon and the lightest stable particle (LSP). This means that you could have events where the photons arrive late when compared to expectation from prompt photons (“delayed photons”) The EMTiming system allows us to look for photons coming from decays with lifetimes larger than nanoseconds

  4. Data Selection We want to validate the tracking (z and timing) and the EMTiming system for the 5fb-1 data set so that it can be used for the delayed photon analysis e/g z = 0 W n We do this by using Wen events because they use all of these systems. Additionally, if we ignore the track from the electron this becomes a g+MET event, but the track information tells us which vertex is the right vertex

  5. Data Selection Wen Candidates: Missing Et > 25 GeV  Central EM Cluster Et > 20.0 GeV (Et Calculated from z = 0) PMT Asymmetry < 0.6 Z Electron Track < 70 cm Using Photon GoodRunList 31 (Luminosity ~ 5.2 fb-1),requiring EMTiming system to be present  Luminosity ~ 4.5 fb-1

  6. We will want to calibrate the Central Outer Tracker (COT) Run-by-Run to TVertex = 0 ns. Vertex Time These are low luminosity runs. We are considering removing all runs w/ luminosity < 100 nb. (This removes 1% of the data, but 25% of the runs) At the time of writing this talk these calibration procedures have not been carried out yet… I will show the remaining plots without calibration for completeness

  7. Right Vertex t vs Right Vertex z Vertex Z fit: y = -0.037x-0.057 The collisions are not centered at z=0 because of Tevatronbetastarfocusing. This is a small effectand can be easily taken into account… See Asaadi SUSY Talk Feb. 09

  8. One way to calibrate the COT is to pick events that come from +/- 2 ns and use those zero the timing distribution on a Run-by-Run basis Method for estimating Run-by-Run Corrections We see from a preliminary work that we will want to pick runs with enough Luminosity to avoid low statistics (L > 100 nb)

  9. EMTiming Time These events need to have their calibrations re-checked and we are in the process of correcting them Zooming In EMTiming is pretty well calibrated, we may consider calibrating the EMTiming system to itself for t=0 later

  10. Time of Flight We expect the Time of Flight to have an offset of ~ 30 picoseconds since the collisions are not actually centered at Z = 0.

  11. Corrected Time (tcorr ) Before applying any corrections we have a mean of 0.08 ns and an RMS of ~0.7 (Pretty good and near our expectation) However, we have tails we need to understand/correct for. Zooming In These events are the need for the corrections to the EMTiming Calibrations already mentioned

  12. Next Steps • Calibration Procedure that we will attempt • Create Run-by-Run corrections for the COT to zero them relative to each other. This has a small effects due to the mean Z not being zero. • Create Run-by-Run corrections for the EMTiming system that subtract off the observed event-by-event t0 and TOF (mean Z is not zero) and calibrate.

  13. Conclusions • We now have the 5fb-1 data set for the delayed photon analysis and have begun the validation and calibration procedure. • At first look, the data is fairly well calibrated (within 80 ps!) with some obvious corrections that need to be made. • We will continue with the calibration procedure for the COT and EMTiming system mentioned previously and attempt to understand the tails in our corrected time distribution.

  14. Back-up Slides

  15. # Path W_NOTRACK_v-241. Trigger L1_EM8_&_MET15_v-11 Bit: [2(9)]1. Specific option L1_EM8_v-3 Instance of PHOTON.1. NUMBER = 12. ET_CENTRAL = 8 GeV3. ET_PLUG = 8 GeV4. HAD_EM_CENTRAL = .1255. HAD_EM_PLUG = .0625Generated Down Load (Instance of PHOTON):1. PREFRED_INPUT_BIT = 10 integer2. PREFRED_OUTPUT_BIT = 14 integer3. FRED_INPUT_BIT = 2 integer4. DIRAC_CRATESUM_BIT_NO = 14 integer5. DIRAC_CRATESUM_BIT_CONTENT = 0 integer6. DIRAC_CRATESUM_WIRE_NO = 10 integer7. DIRAC_MEMORY_BIT_NO = 5 integer2. Specific option L1_MET15_v-3 Instance of MET_PULSAR.1. ET = 15 GeVGenerated Down Load (Instance of MET_PULSAR):1. FRED_INPUT_BIT = 3 integer2. PREFRED_OUTPUT_BIT = 56 integer3. PREFRED_INPUT_BIT = 0 integer2. Trigger L2_CEM20_MET20_v-1 Bit: [21(3)]1. Specific option L2_CEM20_v-2 Instance of PhotonCluster.1. ABS_ETA_MAX = 1.12. ABS_ETA_MIN = 03. CLUSTER_PASS = 144. ET = 20 GeV5. ET_TOTAL = 0 GeV6. HAD_EM = .1257. ISO_ET = 999 GeV8. ISO_FRACTION = 9999. NUMBER = 12. Specific option L2_MET20_v-1 Instance of GlobalMisEt.1. ET = 20 GeV2. MET_TYPE = 23. Trigger L3_W_NOTRACK_MET25_v-61. L3 Instance: metCut25_v1, of class L3MetFilterModule_v-11. MetCut = 25.02. L3 Instance: photon25_v3, of class L3EMFilterModule_v-21. CalorRegion = 22. cenEt = 25.03. cenHadEm = 0.1254. cenHadEmCeiling = 99995. nEmObj = 16. nTowersHadEm = 37. plugEt = 25.08. plugHadEm = 0.1259. plugHadEmCeiling = 9999 # Path SUPER_PHOTON70_L2_EM_v-91. Trigger L1_JET20_v-1 Bit: [27(8)]1. Specific option L1_JET20_v-1 Instance of JET.1. NUMBER = 12. ET_CENTRAL = 20 GeV3. ET_PLUG = 20 GeV Generated Down Load (Instance of JET):1. PREFRED_OUTPUT_BIT = 5 integer2. PREFRED_INPUT_BIT = 1 integer3. DIRAC_MEMORY_BIT_NO = 1 integer4. DIRAC_CRATESUM_BIT_CONTENT = 1 integer5. DIRAC_CRATESUM_BIT_NO = 1 integer6. DIRAC_CRATESUM_WIRE_NO = 1 integer7. FRED_INPUT_BIT = 27 integer 2. Trigger L2_EM70_v-6 Bit: [68(2)]1. Specific option L2_EM70_v-4 Instance of PhotonCluster.1. ABS_ETA_MAX = 3.62. ABS_ETA_MIN = 03. CLUSTER_PASS = 144. ET = 70 GeV5. ET_TOTAL = 0 GeV6. HAD_EM = .1257. ISO_ET = 999 GeV8. ISO_FRACTION = 9999. NUMBER = 1 3. Trigger L3_PHOTON_70_v-41. L3 Instance: photonSuper70_v2, of class L3EMFilterModule_v-21. cenEt = 70.02. cenHadEm = 0.23. cenHadEmScaleFact = 0.0014. nEmObj = 15. nTowersHadEm = 36. plugEt = 70.07. plugHadEm = 0.28. plugHadEmScaleFact = 0.001

  16. Central Baseline Electron Cuts

  17. Motivation for Looking at Exclusive Photon + Missing Energy • An earlier study found an excess in the exclusive Photon + MET sample • Photon ET > 45 GeV • MET > 45 GeV • Veto Jet ET > 15 GeV • Veto Lepton ET > 10 GeV Previous study assumed that the backgrounds were symmetric around t = 0. Our Preliminary Studies are showing this is not a good assumption We want to revisit this analysis using the knowledge we’ve gained from our study of the possible backgrounds and a larger data set to examine what this excess could be

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