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PID & FPD SoftwarePID & FPD SoftwareGilvan Alves

(Lafex/CBPF)

Q4D SQ2Q2Q3 Q3Q4S

A1QA1S

A2QA2S

P1Q

P2S

P1S

P2Q

p p

Z(m)

AD1

Detector

Roman Pot

233359 3323057

Aug 28, 2003

• Overview • Software Tools

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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

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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.

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A fiber PLANE (U, V, X) hasTwo 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 viewof the detector

Scatteredproton

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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-planeU-plane

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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

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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

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LM and Multiple Interaction Rejection

Multiplicity more efficient than Time

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L3L3

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 Elong

Released for production

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PID Certification Document

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Selection Cuts for Elastic Data

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Backgrounds

PID Criteria need to revisited for new data

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We have the following ToolsWe 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

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WV

RA

WV = Wanda, Vladimir CM = CarleyRA = Rafael, Antonio MS = Mike Strang

MSMS

CM?

Trigsim

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What is (still) missingWhat 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