? Physics Program - Vector Meson suppression

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? Physics Program - Vector Meson suppression
A signature of Quark-gluon plasma (QGP) is the
suppression of J/? production. The formation of
J/?s in a QGP is predicted to be inhibited by
color-screening.
NA50 -- Anomalous J/? suppression. Evidence for
QGP??
?A ?pA?
PHENIX simulated ??- mass spectrum
But J/?s are also suppressed by non-QGP effects
such as absorption, shadowing, etc as seen in
the results from our E866/NuSea measurements at
Fermilab.
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? Physics Program - High-pT Single ?s

• High-pT single-?s come from heavy mesons, i.e.
  Ds or Bs
• These mesons are produced primarily through gluon
  fusion and thus are sensitive to the gluon
  structure functions.
• In p-A collisions the shadowing of gluons can be
  studied

• With polarized beams the gluon polarization, ?G,
  can be studied.
• W? ? ?? ?? can be identified by high-pT
  single-?s and W/W- can be used to measure the
  flavor asymmetry in the nucleon sea including its
  spin decomposition

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MVD Physics Program

• Multiplicity Vertex detector (MVD), e.g. for
• dN/d? for charged particles over very broad
  rapidity range
• fluctuations in charge particle distributions,
  e.g. DCC.
• ?(Zvertex) lt 2 mm for the rest of PHENIX

PHENIX w/o MVD ? lt 0.35
STAR ? lt 0.5
dN/d? from MVD for 125 Au-Au events
dN/d? from MVD for one Au-Au event
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MVD vertex resolution efficiency for p-p, p-Au
Au-Au collisions
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Parton Energy Loss
dE/dx 0
dE/dx 0.25
Charged hadron and ?0 production at PHENIX versus
pT for central collisions which, when compared to
pQCD models that work well for peripheral
collisions, suggest that jet-quenching or
energy-loss may be present.
Analysis of our p-A Drell-Yan data using the
Kopeliovich model. Dashed lines with shadowing
only solid lines with parton energy loss
of, dE/dz 2.32 ? 0.52 ? 0.5 GeV/fm
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Accomplishments

• Completion of South ?-arm
• chamber construction
• develop, prototype, debug FEE
• install chambers and FEE
• integrate with PHENIX
• shakedown without beam and reduction of FEE noise
  levels
• Brooks, Mischke, Lee, Leitch, McGaughey, Barnes,
  Liu (PD), Towell (PD)
• Sondheim, Boissevain (engineers)
• Commisioning of MVD (60)
• MCM problems - poor yield --gt cost overruns
• DAQ electronics problems identified and fixed
• Sullivan, Van Hecke, Hansen (PD)
• Quark energy-loss in nuclei using FNAL Drell-Yan
  data
• approach with Kopeliovich using his model
• Johnson, Moss, Peng, Garvey, McGaughey, Leitch
• J/? Nuclear dependence in p-A paper - LeitchE866
• Hard Processes RHIC Physics workshop held last
  summer right after Cerro Grande fire -
  Johnson, Leitch.
• eRHIC - Garvey, Peng NPP long-range plan - Peng,
  Garvey, Moss, McClelland .
• Secured construction for North ?-arm FEE and
  began planning, purchases, fabrication - Brooks
  ...

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PHENIX South ?-spectrometer

• Three very large detector stations in 8 octants
  with 20,000 anode wires and 22,000 cathode
  strips, each cathode strip read out by a low
  noise electronics channel
• 8 meters high and weighs around 300 tons
• over 10 miles of cables

South-? Spectrometer completed now installed at
intersection region - a huge success for the LANL
led team!
Intersection region (and where MVD goes)
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muTr Mechanics
Winding wires for Station-3 at the BNL factory
Station-2 Chamber being hoisted into South ?
magnet
Station-3 Chamber at the construction factory
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South-? FEE
Chassis
Station-3
CROC board
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Supporting ?Tr Electronics
Transition between fiber (outside magnet) and
copper signals (inside magnet)
Cathode strip calibration system
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MVD
Multi-chip Modules (MCM)s
200 ?m silicon strips
After a valiant effort by a core group of 3 LANL
people, 60 of total channels will be installed
and ready for beam in May. (90 by late 2002)
1/4 of partially populated MVD

• lt 1 radiation length
• 38,000 channels of strips pads
• MCMs 256 channels compressed on to a 4-layer
  board smaller than a credit card
• 70 cm long x 2 feet diameter
• Total weight 20 lbs

MVD in its enclosure
MCM with a dime for scale
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People Highlights of Responsibilities

• Staff (widespread involvement in new physics
  initiatives not listed here)
• Barnes (1/2 on EDM, return-to-research ends
  this year) N? mechanics, S? physics.
• Brooks ?-tracking PHENIX DC manager,
  ?-software, N? FEE, S? physics
• Garvey (1/2 retiring soon) not involved in
  PHENIX, E866, eRHIC workshops, advisor to BNL
  John Browne, RHIC program supporter.
• Lee N? mechanics manager, HV, S? physics.
• Leitch HENP team leader, N? FEE, ?-calibration
  system, ?-software, S? physics, J/? suppression,
  E866 spokesman, PHENIX Executive Council
• McGaughey N? FEE, ?-calibration system,
  ?-software, S? physics, parton enegy-loss, former
  E866 spokesman.
• Mischke (moving to other areas) was S? FEE
  manager, N?-FEE consultant, S? physics.
• Moss spin physics, parton energy-loss, APS DNP
  chair.
• Peng (1/4 time on EDM) E866 physics, parton
  energy-loss, p-A, PHENIX upgrades, parton physics
  at PHENIX, FNAL P906, JHF.
• Sullivan MVD PHENIX DC manager, hadron
  physics, MVD FEE software.
• Van Hecke MVD ancillary systems DAQ, hadron
  physics
• Postdocs
• Hansen hadron physics, MVD FEE software.
• Liu S? FEE, ?-software physics, spin physics
• Towell S? N? mechanics physics
• Engineers
• Boissevain (1/4) MVD constuction, ? layout.
• Sondheim (on construction ) lead engineer
  PHENIX ?

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Large Presence at BNL

• Full time at BNL
• John Sullivan change-of-station for one year
  (starting 1/15/01)
• Three postdocs Hansen, Liu Towell
• More than half-time at BNL
• Brooks more than 80 for recent months
• Leitch more than 80 for recent months
• Mischke
• Sondheim
• Substantial time at BNL
• Lee, Van Hecke, Boissevain, Barnes
• Large contributions to Long-range planning
  exercise
• Peng, Moss, Garvey