1. 1 PID & FPD Software Gilvan Alves (Lafex/CBPF) Q4Q4 D S Q2Q2 Q2Q2 Q3Q3 Q3Q3 Q4Q4 S A 1Q A1SA1S A 2Q A 2S P 1Q P 2S P 1S P 2Q p p Z(m) A D1 Detector Roman Pot 233359 33230 57 Aug 28, 2003 Overview Software Tools

2. 2  Definition of the object class - proton  Tools for estimating rates and efficiencies of the objects (p/pbar)  Algorithms for offline reconstruction relevant to the object ID  Algorithms for L1/2/3 Triggers  Development of the analysis tools that define the quality of the object  Calibration of the objects - understand resolutions  Online and Offline software

3. 3 FPD objects  FPD Tracks  HIT = Coincidence between U and V planes confirmed by a X plane  Track = Two HIT’s in a spectrometer (2 pots) constrained to the DØ IP.  Halo `Track`  Early-time hits in trigger scintillator (60-90 ns) before crossing  Possibly in « coincidence » with in-time hits in opposing spectrometer.

4. 4 A fiber PLANE (U, V, X) has Two layers of parallel fibers (U, U’; V, V’; X, X’) Offset by 2/3 fiber spacing A HIT is defined as Combination of fibers in the two LAYERS. 20 + 20 fibers gives 79 possible HIT values with 0.27/  12 mm resolution. FPD Detector Hit Bottom view of the detector Scattered proton

5. 5 FPD Detector Position The U and V planes are oriented at ± 45.º A U-HIT & V-HIT determines position of a track (There are 4,128 U-HIT & V-HIT combinations.) Signals in X and X’ layers used for confirmation, ghost hit elimination, and to measure fiber hit efficiency. V-plane U-plane

6. 6  A TRACK is determined from the positions in two FPD detectors (straight line, with small correction for electrostatic separators and quadrupoles)  There are (4,128) 2 ~ 17 M track combinations (equations) Only some are consistent with origin at the IP.  Adding DØ IP as constraint:  Determines momentum and scattering angle  Reduces number of equations to ~ 500 k  Very large number of equations  Use ranges of ( , | t |) to reduce number;  One FPGA (Virtex 2000 ?) per spectrometer  Three double-wide DFE  We already have a full set of equations for L1 trigger FPD Detector Track

7. 7 Halo and Multiple Interactions X Early time hits t = 0 Reject Halo hits using trigger scintillator timing info Multiple Interactions pile-up Single Diff. p (pbar) + Dijet Large for quadrupole (low  ) and small for dipole (high  ) Level 1 cut (  > 0.004) reduces overlap to 5% Level 3 SI tool could further reduce pile-up

8. 8 LM and Multiple Interaction Rejection Multiplicity more efficient than Time

9. 9L3 L3Unpack Tool: Preliminary version available and being tested Tracking Tool: Fast implementation of the offline tracking Test/Prod released Improvements in ghost tracks rejection Single Interaction: Vertex information implemented Already in CVS Including Calorimeter information on E long Released for production

10. 10 PID Certification Document

11. 11

12. 12 Selection Cuts for Elastic Data

13. 13 Backgrounds PID Criteria need to revisited for new data

14. 14 We have the following Tools  Generate and Process MC full chain (need to be tested) Diffractive Generators(pompyt, pomwig, phojet, scipyt) in the release FPD geometry+ beamline in d0gstar+d0sim => FPDDigiChunk => FPD_RECO  Filter events at L3 (given L1 & L2 bits are set) Tracking, Unpacking Single Int. Tools in the release (not tested on raw data)  Process events offline (standalone now - needs d0reco integration) Unpacking - released - tested on raw data FPD_Reco - released - needs raw data testing Geometry - pre-release version  Database access (offline)  Control/Monitor Pot movement, HV Roman Pot movement - Python - stable version, more automation in progress  Online Examine pre-release version

15. 15 WVWV RARA WV = Wanda, Vladimir CM = Carley RA = Rafael, Antonio MS = Mike Strang MS CM ? Trigsim

16. 16 What is (still) missing FPD_Reco Integration D0Reco Trigger Simulator Raw Data + Trigger Info Forward Vertexing L3 & Offline L3 Geometry == Offline?? DST&TMB info D0reco FPD_Analyze Offline (DST+TMB) Alignment Tool (offline?) Elastic stream Calibration Tool (offline) LMB+Data