Ideas for a Comprehensive New Detector for InDepth Study of the QGP and Spin Physics at RHIC II

1
R2D The Case for a comprehensive 2nd generation
RHIC detector
R. Bellwied (Wayne State University) for the R2D
working group
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A New Frontier for Heavy Ion Physics ?

• We discovered strongly coupled partonic,
  collective matter (sQGP), which is interesting in
  itself but it will not secure the future of our
  field.

• Where do we go from here ? What unique physics
  can RHIC-II (40 RHIC-I design luminosity _at_ 200
  GeV) provide during the later stage of the LHC
  era beyond 2013 ?

• What are the detailed properties of the sQGP and
  what are the degrees of freedom at high densities
  ?
• What is the mechanism of hadronization and is
  chiral symmetry restored in the deconfined medium
  ?
• Is there another state (CGC) of matter at low x,
  what are its features, and how does it evolve
  into the QGP ?
• What is the structure and dynamics inside the
  proton (parton spin, L) and what do we learn
  from parity violation and polarization
  measurements ?

3
How strong is the sQGP at RHIC and beyond ?
Different initial conditions at RHIC and LHC
?? Prediction v2 should decrease
4
RHIC-II - a unique place to study hadron
formation out of a medium

• Questions
• What are the degrees of freedom above Tc ?
• Do deconfinement and chirality decouple ?
• How is baryonic mass (universe) generated from a
  medium ?

• Models Recombination
• constituent quark (dressed up valence quarks)
• A. Peshier (hep-ph/0502138)
• quasi particles above Tc
• E.Shuryak (hep-p/0405066)
• colored colorless bound states above Tc
• R.Rapp (hep-ph/0505080)
• quasi-resonant heavy states above TC

Levai/Heinz (massive partons)
(hep-ph/9710463)

• Measurements
• Particle identified measurements of v2 , jet
  quenching, resonance shifts and rapidity
  instabilities
• Ratios of particles with common valence quarks
  (e.g. p/h) (T.Peitzmann QM poster)
• Baryon strangeness number correlations (probes
  bound states) (V.Koch QM talk)

5
pp at RHIC Hadron formation in QCD NLO for
heavy masses requires quark separation in
fragmentation function ?
In AA is the fragmentation function modification
due to the partonic medium universal ?
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RHIC-II a unique place to study energy loss
fragmentation in the strong coupling limit
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RHIC-II a unique place to study low-x physics ?

• Color Glass Condensate (CGC)
• gluon saturation at low Q2. Measure
• Mid forward rapidity correlations
  (hep-ph/0403271)
• Direct photons at forward rapidities
• gg HBT (coherence of sea-quark source?)
• Drell-Yan in forward region (hep-ph/040321)
• RpA, RAA of heavy mesons in forward direction
  (hep-ph/0310358)
• requires tracking, calorimetry and PID over large
  h-range.

8
RHIC-II a unique place to study the complete
onium program

• Melting of quarkonium states (Deconfinement TC)
• Tdiss(Y) lt Tdiss(?(3S)) lt Tdiss(J/Y) ?
  Tdiss(?(2S)) lt Tdiss(?(1S))
• In order to resolve the question of melting of
  the states and its relevance to the sQGP we need
  to measure
• the J/y production mechanism (octet vs. singlet
  model) (requires pp)
• the effect of nuclear absorption (requires pA)
• the effect of thermal recombination
• the effect of co-mover absorption
• the feed-down from cc (in pp, pA,AA)
• all states (in pp, pA, AA)

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Requirement track-by-track PID at high pt in
large acceptance !
2p
STAR, 4 GeV
R2D, 25 GeV
10 GeV
PHENIX
f
4 GeV
0
-4 -3 -2 -1 0 1 2 3 4 h
Trigger on flavor tagged jet or photon and
measure particle composition
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Requirement full coverage and excellent
resolution in tracking, and calorimetry

• h and pT broadening for gjet

g distribution for cc decay
R2D
Y States resolution in R2D
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R2D detector concept hermeticity and PID
The Ultimate Heavy Ion Detector Combine high
energy experiment precision, hermeticity, field
strength and calorimetry with heavy ion
experiment capabilities in particle
identification and tracking. Prohibitively
expensive ?? (requires the utilization of
decommissioned HEP detector components (from
SLAC, FNAL, DESY)) In particular use existing
magnet, calorimetry, muon chambers
electronics Build new particle identification
and tracking Projected price tag lt 100 Million
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Alternative S-R2D based on CDF(CDF, CLEO
BABAR have same field and magnet radius)
SC Coil R 1.5 m Bz 1.5 T
EMC, CsI crystal, 24 X0
Si Strip Detectors
AeroGel2 Ch. D.
AeroGel1 Ch. D.
HC and Muon Detectors
Rcoil 150 cm
Gas RICH Detectors
Si Vertex D.
GEM Tracking D.
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Comparison of RHIC-II/LHC onium programs per run
year (thanks to T.Frawley)
For more detail dA http//rhicii-heavy.bnl.gov
/doc/April05Meeting/frawley-lhc-rhich.pdf
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Comparative Physics Reach
Deconfinement, chirality and low x physics a.)
Onium physics Y J/Y cc
Y(1s) Y(2s) Y(3s) b.) Rapidity
gap measurements and forward physics Dh gt 1
gt 2 gt 3 gt 4 gt 5
gt 6 c.) Chirality measurements low mass
di-lepton chiral partnersresonances gt
Tc d.) Degrees of freedom above Tc (w. PID)
v2 gt 4 GeV/cR(AA) h1v2 gt 10 GeV/cR(AA)
h3
Fragmentation and hadronization a.) Di-hadron
jets 10 GeV 20 GeV 30
GeV 40 GeV b.) Gamma-jet
with identified hadrons (h gt 5 GeV/c) 5 GeV g
10 GeVg 15 GeVg
20 GeVg c.) Identified high pt di-hadron
correlations pp gt 3 GeV/c gt 5 GeV/c gt 10
GeV/c LLgt 5 GeV/c
R2D a unique device for RHIC-II
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Why RHIC-II and R2D in the LHC era ?

• RHIC-II with R2D is a unique place to study
• hadron formation in the strong coupling limit
• differences between quark and gluon jet
  properties
• energy loss and fragmentation in the strong
  coupling limit
• saturation as a function of x
• a complete onium program
• Independent of the evolution of the system, the
  initial conditions will be different. This
  provides a unique situation, which allows us to
  study hadron formation and new phases of matter
  in two different energy regimes.
• RHIC-II with R2D offers longer running time,
  higher luminosity, more detailed detector
  capabilities. LHC offers higher energy and larger
  cross sections.

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Expression of Interest -A Comprehensive New
Detector for RHIC II
P. Steinberg, T. Ullrich (Brookhaven National
Laboratory) M. Calderon (Indiana University) J.
Rak (University of New Mexico) S. Margetis,
C.Markert (Kent State University) M.A. Lisa, D.
Magestro, B. Petrak (Ohio State University) R.
Lacey (State University of New York, Stony Brook)
G. Paic (UNAM Mexico) T. Nayak (VECC Calcutta)
R. Bellwied, C. Pruneau, S. Voloshin (Wayne
State University) and H. Caines, A. Chikanian,
E. Finch, J.W. Harris, M. Heinz, M.A.C. Lamont,
J. Sandweiss, N. Smirnov, R. Witt (Yale
University) (80 pages, submitted in August
2004,nucl-ex/0503002)