Forward Proton Detector Update

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Forward Proton Detector Update
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P1U
P2O
Andrew Brandt, UTA
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P1D
P2I
Veto
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Z(m)

• 9 momentum spectrometers comprised of 18 Roman
  Pots
• Scintillating fiber detectors can be brought
  close (6 mm) to the beam to track scattered
  protons and anti-protons
• Reconstructed track is used to calculate momentum
  fraction and scattering angle
• Much better resolution than available with gaps
  alone
• Cover a t region (0 lt t lt 3.0 GeV2) never before
  explored at Tevatron energies
• Allows combination of tracks with high-pT
  scattering in the central detector

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Outline

• Personnel and Physics Goals
• Hardware/Operations
• Trigger
• Elastic Analysis
• Software
• Outlook and Plans

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UTA FPD Personnel/Resources
Andrew Brandt (UTA) FPD L3 Manager Fermilab-base
d Michael Strang (UTA GRA) data
analysis Duncan Brown (UTA post-doc) operations,
trigger, diffractive physics (May
04-- UTA-based Ricardo Ramirez (UTA EE GRA)
trigger firmware No longer employed by
UTA Daniel Mendoza (UTA EE) readout and trigger
commissioning Funding DOE OJI (81k), NSF MRI
(NIUUTA 125,000, equipmentGRA for 2 years
through Aug. 05) , 6 months post-doc from UTA VP
for research (one time seed money) start-up, ARP
finished
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Other FPD Senior Personnel
Brazil Gilvan Alves, general software (3
months Fermi) Jorge Barreto, tracking (0)
Marcia Begalli, detector commissioning (6
months) Jorge Molina, data analysis (3 months)
Maria Elena Pol, detector commissioning (4
months) others with smaller DØ research
fractions Columbia Carlos Avila, alignment (3
months) FNAL 200k support for Brazilian and
Columbian visitors for 2004-2005 (FPD
Luminosity Monitor)
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DØ Run II Diffractive Topics
Soft Diffraction and Elastic Scattering
Inclusive Single Diffraction Elastic
scattering (t dependence) Total Cross
Section Centauro Search
Inclusive double pomeron
Search for glueballs/exotics Hard
Diffraction Diffractive jet
Diffractive b,c ,t , Higgs
Diffractive W/Z
Diffractive photon Other
hard diffractive topics Double
Pomeron jets Other Hard Double Pomeron
topics
Rapidity Gaps Central gapsjets Double
pomeron with gaps Gap tags vs. proton tags
Topics in RED were studied with gaps only in Run
I
lt100 W boson events in Run I, gt100 tagged events
expected in Run II
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Diffractive Topics and Students!
Student (Year) Institute Advisor Subject
Tamsin Edwards (2004) Manchester Cox Diffractive Z (gaps)
Vlatislav Hynek (2007) CTU Simak Diffractive Forward jets
Ana Carolina de Jesus (2007) UERJ Santoro Diffractive Heavy Flavor
Helena Malbouisson (2007) UERJ Santoro Diffractive structure fct
Luis Mendoza (2007) Bogotá Avila Diffractive W, Z
James Monk (2006) Manchester Cox Double Pomeronjets
Murilo Rangel (2008) UFRJ Barreto Diffractive chi_c
Renata Rodrigues (2007) UERJ Santoro Elastic/Diffractive/ Double Pomeron
Michael Strang (2004ish) UTA Brandt Diffractive jets
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Detector/Castle Status

• All 6 castles with 18 Roman pots comprising the
  FPD were constructed in Brazil,
• installed in the Tevatron in fall of 2000, and
  have been functioning as designed.
• 20 detectors built over a 2 year period at UTA
• In 2001-2002, 10 of the 18 Roman pots were
  instrumented with detectors.
• During the fall 2003 shutdown the final eight
  detectors and associated readout
• electronics were installed.

A2 Quadrupole castle with all four detectors
installed
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Pot Motion Software
Pot motion is controlled by an FPD shifter in the
DØ Control Room via a Python program that uses
the DØ online system to send commands to the step
motors in the tunnel.
The software is reliable and has been tested
extensively. It has many safeguards to protect
against accidental insertion of the pots into
the beam. CDF accident in 12/03 grounded TeV for
2 weeks, pots for 1 month.
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Operations

• Operations in 2004 have been routine, only
  occasional minor problems, much less than average
  sub-detector
• Currently FPD expert shifters inserts pots and
  Captains removing pots and setting system to
  standby
• 18 pots inserted every store when lumlt45E30, note
  in 2003
• we often only inserted dipole pots due to
  readout commishioning
• Combine shifts with CFT, since similar readout
  system,
• standard FPD fiber plots incorporated into
  CFT online
• examine program
• Working towards automated pot insertion by shift
  captain

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Detector Hit Resolutions

• Starting in January 2004, all 18 detectors
  regularly inserted (dipoles since February 2003)
• Commissioning underway on quadrupoles
• Resolutions calculated by the difference of the x
  value of a hit calculated from u/v segments
  compared to the x value of the x segment show
  that most of the detectors are working as expected

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FPD Trigger and Readout
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FPD Readout
Front View of PW08 (11/10/03)
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2004 Fall Shutdown Work

• Done
• Repair P2I and A2O (light leak tests), move to
  one spectrometer
• Investigate A1O first step in problems
• Test spare multiplexorcontrol boards, spare
  PMTs
• Camera repairs
• Survey before and after separator alignment
  changes
• Ground searchesrepairs
• In Progress
• Investigate any cabling/mapping problems
• Replace veto counters and veto PMT'ssurvey
• Trigger commissioning
• LM commissioning
• Automatic pot insertion tests

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Trigger Team

• Andrew Brandt (Trigger Logic/List/Oversight)
• Duncan Brown (Trigger Implementation)
• Mario Vaz (FPD DFE equations/TM firmware)
• Wagner Carvalho (DFE equations/test vectors)
• Ricardo Ramirez (FPD/DFE Interface)
• Tom Fitzpatrick (FPD/DFE Interface/DFE Timing)
• Brian Cox, Dave Mercer, Scott Kolya (LM)
• Carlos Avila, Luis Mendoza (Stand-alone trigger)

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Current Diffractive Triggers
Jet Gap(s) JT_15TT_GAPN or S CJT(2,3)GAP
L3(1,15) Prescaled, currently .3-.4 Hz each
Llt40E30 lt.1Hz at 40 E30 JT_15TT_GAPSN
CJT(2,3)GAPS L3(1,15) Currently unprescaled 0.6
Hz at 40E30 small prescale above JT_45TT_GAPN
or S CJT(2,5)GAP L3(1,45) Currently prescaled
by 2 at 60E30 .08 Hz each JT_45TT_GAPSN
CJT(2,5)GAPS L3(1,45) Unprescaled at all
luminosity 0.03 at 40E30
J/?? Gap(s) 2MT1_2TRK_GAPN 2MT1_C_2L2L_2TRK
ALMNorthv 2MT1_2TRK_GAPS 2MT1_C_2L2L_2TRK
ALMSouthv 2MT1_2TRK_GAPSN 2MT1_C_2L2L_2TRK
ALMSouthvALMNorthv Unprescaled at all
luminosity These triggers are being used to
search for exclusive J/?? and ?C , a key
step towards validating diffractive Higgs models
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Trigger Manager Inputs

• FPD_LM
• Information on which detectors are hit and
  halo
• 2) LM pass through 16 LM and/or terms
• includes GapN GapS GAPSN SI etc.
• mostly can get this info separately
• DFE information from scintillating fiber
  detectors,
• forseen to give ?, t now using segment
  information, multiplicity

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FPD-LM

• TDC Details
• Step I TDC in readout
• 3 TDC boards for FPD compared to 6 LM boards
• 1 board consists of Px1, and Ax1 where
  xUp,Down, In,
• Out pots (first quadrupole castle on
  either side of IP)
• 2 board consists of Px2, and Ax2
• (second quadrupole castle)
• 2 dipoles 4 veto counter signals
• Step II Add halo bit information to TDCs
  (shutdown)
• Step III Pass bit info to vertex board (and then
  to TM)
• and add scalar info (December?)

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2004 Trigger Strategy

• Input information
• Currently no global run trigger capability
• LM Vertex board is delayed (may now be finished
  during shutdown)
• DFE boards and TM work and ready to be
  commissioned
• Main background not from pileup (multiple
  interactions) but from halo spray
• Strategy
• Instead of calculating bins of ? and t, use
  fiber hit patterns to demand 2 or 3 out
• of 3 planes of each detector are hit.
  Replaces trigger scintillator, simpler algo
• Use multiplicity cut to reject halo spray, code
  several multiplicity levels
• NOTE fiber ADC threshold must be high enough to
  avoid noise, low enough
• to retain efficiency and allow vetoing
  of halo
• One advantage is pot positions not needed at
  trigger level
• Issues
• Setting ADC threshold, need special run (and
  analysis)
• Dealing with noisy channels, variable means,
  could initially set threshold high,
• later load in mean pattern, known hot
  channels
• Measure efficiency with jet triggers, scint
  triggers from special runs
• Exposure groups, triggers in global run or
  separate global run

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Exposure Groups etc.

• For normalization purposes each trigger is
  assigned an exposure group
• and live time is measured for that
  groupdifferent beam conditions require
• different groups
• Only 8 exposure groups (6 used), we have more
  combos so must
• operate outside exposure groupsnew value
  NOLUM
• This is a trigger database change which was
  requested more than one
• year ago and was hostage to internal
  Fermilab DØ/CD politics
• Now estimated completion of DB work is January
• Once FPD DFE/TM is ready we are mostly restricted
  to dedicated special
• runs until database issue resolved

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Interim Trigger Plan

• Proceed with DFE/TM debugging during shutdown
• Since current FPD commissioning is special run
  intensive and
• new elastic triggers with adjacent
  spectrometer veto have rates
• around 1 Hz, we proposed adding an elastic
  trigger to first post-shutdown
• global trigger list
• This will only take one exposure group and allow
• us to obtain good elastic sample at lums
  lt45E30
• accepted by trigger board, will be
  operational in December

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Trigger Progress

• DFE/TM chain tested by Duncan with help from
  Jamieson and Jeff Temple, works with simple test
  firmware. All hardware works.
• Two versions of DFE firmware developed by
  MarioRicardo, being incorporated by Tom into
  standard DØ framework.
• Early failures traced to delays between different
  inputs to DFE, Tom worked out solution similar
  to TM, which waits for all inputs before
  processing Duncan just tested successfully.
• 4. Ricardo is working on arbiter, which is
  necessary to add outputs from 3 spectrometers to
  form 96 bit DFE word sent to TM. He has produced
  a 3-chip testbench to simulate full DFE,
  simulations work, about to be tested on platform.
• 5. Jeff Mario produced first version of TM
  firmware, Duncan testing it this week.

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V4 TM Algorithm
DFE will pass word for each spectrometer
indicating coincidence of two detectors tight
track exactly 1 hit with 3/3 fine segments in
each detector medium gt0 with 2/3 lt20 wide
segement loose gt 0 with 2/3 lt20 wide
segement At TM we form terms DIFFany
spectrometer track DIFFQany quadrupole
spectrometer track (could be false if gt1 or 2 on
A or P side) DIFFDdipole track ELASAU-PD or
AD-PU or AI-PO or AO-PI DPOMAU-(PU or PI or PO)
or AD-(PD or PI or PO) or AI-(PU or PI or PD) or
AO-(PU or PD or PO)DI -(PU or PD
or PO or PI) OVERAU-DI or AD-DI or AO-DI or
AI-DI (over-constrained track for alignment)
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FPD Trigger List
Tentative L1 FPD V14 trigger list (early 2005)
1) elastic (diag opposite spectrometers)
GAPSN 2) soft diffraction (single
spectrometers)GAPS or GAPN 3) overconstrained
track (pbar in quadrupole dipole
spectrometers)GAPN 4) double pom (up-up, dn-dn
etc.)GAPSN if needed 5) CJT(2,3) FPD Track
(DIFFQ or DIFFD) GAPS or GAPN if needed 6)
CEM(1,3) FPD track GAP (if needed) 7)
TTK(1,1.5) FPD track GAP 8) MU(1,x) FPD track
GAP Rates are not yet well known. If 4 (dpom)
it is not low enough to run unprescaled we would
need to repeat 5-8 with two FPD tracks.
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Special Run Trigger
In-time hits in AU-PD detectors, no early time
hits, or LM or veto counter hits
Current NIM logic allows us to form several
elastic and diffractive triggers for special
runs using trigger scintillators (in parallel
information from scintillators is sent to TDCs
for commissioning FPD_LM system, and CAMAC
scalars), veto counters, and LM. Can trivially
switch from elastic to double pomeron (Aup-Pup
for example)
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Elastic Scattering

• Elastic scattering ? 0 (no momentum lost by
  beam particle)

• Quadrupole acceptance
• t gt 0.8 GeV2 (requires sufficient scattering
  angle to leave beam envelope)
• all ? (no longitudinal momentum loss necessary)

• Measure dN/dt for elastic scattering using early
  stand-alone FPD data

• antiproton side
• quadrupole up spectrometer
• trigger only

• proton side
• quadrupole down spectrometer
• full detector read-out

veto on LM and VETO counters, early time hits
(halo tracks)
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dN/dT Result of the week
http//www.fnal.gov/pub/today/archive_2004/today04
-03-18.html
Tremendous work especially by the Jorges to
obtain the preliminary dN/dT measurement.
Congrats again to Dr. Molina for first FPD PhD!
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Separator plates
Fall 2003 shutdown survey data (points AB) made
available by accelerator in April show offsets of
up to 0.7 cm! Required rewriting of MC to
separate separators, reanalysis of acceptance.
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The acceptance for the PD spectrometer
Before sep correction
After sep correction
Much better high-t acceptance (previously high-t
data thought to be halo)
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Elastic Status

• Re-evaluating acceptance and backgrounds based
  on
• new alignment, also studying AU-PD correlations
  
• Will decide soon if data is sufficiently well
  understood to
• publish
• Silver lining nearly 100 of effort directly
  transferable to
• new analyses

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Software Status

• L1 Firmware in good shape
• L3 FPD tracking tools and single interaction
  tools included in latest L3 release
• Offline reconstruction modified to run with
  standard DØ reconstruction program or in
  standalone mode
• Online examine programs incorporated in standard
  shifts
• Alignment and calibration routines being refined
• MC and Analysis software discussed in other talks

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Outlook and Plans

• Finish Level 1 Trigger Commissioning
• Continue routine data collection, add new
  triggersnew data
• samples
• Emphasis on physics/publishing mature results
  and
• obtaining new preliminary results
• Plan to operate FPD through 2006 shutdown,
  perhaps
• periodic special runs after that
• AB will ramp down involvement as commissioning
  phase finally draws to a close continue in a
  consulting role only after mid-2006