29-oct-05panic rhic ii science and perspective with thanks (and apologies) to a. drees, j. dunlop,...
Post on 13-Jan-2016
216 Views
Preview:
TRANSCRIPT
29-Oct-05 PANIC
RHIC IIScience and Perspective
with thanks (and apologies) to
A. Drees, J. Dunlop, A. Frawley, J. Harris, T. Hirano, R. Majka, L. McLerran, J. Nagle, T. Roser, U.
Wiedemann
W.A. ZajcColumbia University
29-Oct-05 PANIC
Science or Perspective?Science or Perspective? Eric Blinman (Thursday’s after-dinner speaker)
“Our investigations are indeed a science, because the stories that I tell are intended to be criticized.”
Implies my remarks will be more perspective than science : My stories aren’t intended to be criticized ;-) My perspective is highly colored by
Planning efforts to fit a hugely varied physics program intoa very finite number of running weeks per year.
Service on the “Tribble Committee” : Our science is under siege We have achieved a temporary respite, won by
Existing successes of the program Intense efforts of P. Barnes, R. Milner, B. Müller, S.
Vigdor(also E. Hartouni, A. Mignery, J. Symons,…)
To continue, we must develop the case for OUTSTANDING science that can survive in a world of finite resources and (often non-logical) constraints.
(Don’t expect me to do that here)
29-Oct-05 PANIC
Science QuestionsScience Questions
Uninteresting question:What happens when I crash two gold
nuclei together? ✔ Interesting question:
Are there new states of matter at the highest temperatures and densities?
$ Compelling question: What fundamental properties of our
gauge theories of nature can be investigated experimentally?
29-Oct-05 PANIC
Simple arguments to motivate a QCD phase transition have a problem: A simple Maxwell construction that predicts TC ~ 140
MeV also predicts a latent heat ~ 0.8 GeV/fm3 However, the lattice tells us that the “real” QCD phase
transition is not a phase transition at all, but a “smooth crossover”
Perhaps related to ignoring the critical role of quark (spin, helicity, chirality):
A gluon can not change a quark’s helicity:
But confinement requires helicity change: “To understand the inside of the proton
you must understand the outside of the proton.” (R. Mawhinney)
Grand ConnectionGrand Connection
BagWall
=
29-Oct-05 PANIC
Grander ConnectionsGrander Connections Theories of the Early Universe
are replete with phase transitions QCD is the only fundamental theory
with a phase transition that is accessible to experiment(!)
Coupling Constant Number Limit
Weak Strong Particle Bulk
Gravity X X
Weak X X
QED X
QCD
29-Oct-05 PANIC
Grandest ConnectionGrandest Connection Emerging understanding(?) of
Regge trajectories: BARYONIC STATES IN QCD FROM GAUGE/STRING
DUALITY AT LARGE N(C), G.F. de Teramond and S.J. Brodsky, hep-th/0409074
Deep Inelastic Scattering: HARD SCATTERING AND GAUGE / STRING DUALITY,
J. Polchinski and M.J. Strassler, Phys.Rev.Lett.88:031601,2002 hep-th/0109174
Entropy: ENTROPY AND TEMPERATURE OF BLACK 3-BRANES,
S.S. Gubser, Igor R. Klebanov and A.W. Peet, Phys.Rev.D54:3915-3919,1996 hep-th/9602135
Viscosity: THE SHEAR VISCOSITY OF STRONGLY COUPLED N=4
SUPERSYMMETRIC YANG-MILLS PLASMA., G. Policastro, D.T. Son , A.O. Starinets, Phys.Rev.Lett.87:081601,2001 hep-th/0104066
via AdS/CFT correspondence
29-Oct-05 PANIC
Disclaimer Disclaimer Yes I know
‘t Hooft limit of N =4 SSYM ≠ QCD I don’t care-
There is as much circumstantial evidence for the utility of these methods as there is for “perfect fluidity” of our sQGP…
Connections like these are essential - not only for progress in the strongly-coupled regime, - but also - for expanding the intellectual breadth and appeal of our
physics: “This suggests that AdS/CFT methods could indeed be useful in
studying the physics of sQGP, and certainly gives strong motivation for continued experimental and lattice research.”
from QCD AND STRING THEORY, I.R. Klebanov, to appear in the proceedings of 22nd International Symposium on Lepton-Photon Interactions at High Energy (LP 2005), Uppsala, Sweden, 30 Jun - 5 Jul 2005, hep-ph/0509087
Disclaimer (well, not Disclaimer (well, not really) really)
29-Oct-05 PANIC
The Uniqueness of RHICThe Uniqueness of RHIC Outstanding questions about strongly interacting
matter: How does matter behave at very high temperature and/or
density? What is the nature of gluonic matter? How does this gluonic matter appear inside of strongly
interacting particles? How are spin and baryon number distributed inside of nucleons?
RHIC addresses all of these:
29-Oct-05 PANIC
RHIC: A Unique QCD RHIC: A Unique QCD LaboratoryLaboratory
QCD
confinement new phases
low xcolor glass
High T, QCP
p-spinstructure
RHIC RHIC upgrades eRHIC
Discovery Exploration Precision R. MilnerR. MilnerWAZWAZ
29-Oct-05 PANIC
Lattice Gauge Theory
Tests QCD Tests Confinement Computes Masses
Compute Finite T QCD
QCDOC Project at BNL promises
10+ TFlops (x 2)allowing for
computations with realistic quark
massesRBRC
29-Oct-05 PANIC
QCD LabQCD Lab
QCD Lab = BNL RHIC + RHIC II + eRHIC + QCDOC + RBRC
A spectacular confluence of science, facilities, and opportunities
29-Oct-05 PANIC
RHIC SuccessRHIC Success
29-Oct-05 PANIC
Success ≠ DoneSuccess ≠ Done BRAHMS:
It is also clear that the unravelling of the physics of the matter state(s) observed at RHIC has just begun. In spite of the impressive advances that have been made in the last three years there are still many issues to be understood in detail, such as the differences in the high pT suppression of baryons and mesons and the quantitative energy and rapidity dependence of the final and initial state high pT suppression. Undoubtedly future measurements will shed new light on these and many other questions. We should not forget, however ,that there are also significant challenges for theory. In the opening chaptersof this document we remarked on the requirement that scientific paradigms must be falsifiable. We have yet to see a fully self consistent calculation of the entire reaction evolution at RHIC that in an unambiguous way demonstrates the impossibility of a hadronic description.
PHENIX: In conclusion, there is compelling experimental evidence that heavy-ion collisions at RHIC produce a state of
matter characterized by very high energydensities, density of unscreened color charges ten times that of a nucleon, large cross sections for the interaction between strongly interacting particles, strong collective flow, and early thermalization. Measurements indicate that this matter modifies jet fragmentation and has opacity that is too large to be explained by any known hadronic processes. This state of matter is not describable in terms of ordinary color-neutral hadrons, because there is no known self-consistent theory of matter composed of ordinary hadrons at th measured densities. The most economical description is in terms of the underlying quark and gluon degrees of freedom. Models taking this approach have scored impressive successes in explaining many, but not all, of the striking features measured to date. There is not yet irrefutable evidence that this state of matter is characterized by quark deconfinement or chiral symmetry restoration, which would be a direct indication of quark-gluon plasma formation. The anticipated program of additional incisive experimental measurements combined with continued refinement of the theoretical description is needed to achieve a complete understanding of the state of matter created at RHIC.
PHOBOS: One of the most important discoveries at RHIC is the evidence that, in central Au+Au collisions at ultra-
relativistic energies, an extremely high energy den- sity system is created, whose description in terms of simple hadronic degrees of freedom is inappropriate. Furthermore, the constituents of this system ex-perience a significant level of interaction with each other inside the medium. These conclusions are based on very general and, to a large extent, model independent arguments. It is not claimed that the observed phenomena are unique to RHIC energies. Nor is it claimed that there is direct evidence in the data analyzed so far for color deconfinement or chiral symmetry restoration.
STAR: The properties already delineated, with seminal contributions from STAR, point toward a dense, opaque, non-
viscous, pre-hadronic liquid state that was not anticipated before RHIC. Deter-mining whether the quarks and gluons in this matter reach thermal equilibrium with one another before they become confined within hadrons, and eventually whether chiral symmetry is restored, are two among many profound questions one may ask. Further elaboration of the properties of this matter, with eyes open to new unanticipated features, remains a vital research mission, inde- pendent of the answer that nature eventually divulges to the more limited question that has been the focus of this document.
29-Oct-05 PANIC
BRAHMS White PaperBRAHMS White Paper
It is also clear that the unraveling of the physics of the matter state(s) observed at RHIC has just begun. In spite of the impressive advances that have been made in the last three years there are still many issues to be understood in detail, such as the differences in the high pT suppression of baryons and mesons and the quantitative energy and rapidity dependence of the final and initial state high pT suppression. Undoubtedly future measurements will shed new light on these and many other questions.
29-Oct-05 PANIC
PHENIX White PaperPHENIX White Paper
In conclusion, there is compelling experimental evidence that heavy-ion collisions at RHIC produce a state of matter characterized by very high energy densities, density of unscreened color charges ten times that of a nucleon, large cross sections for the interaction between strongly interacting particles, strong collective flow, and early thermalization. Measurements indicate that this matter modifies jet fragmentation and has opacity that is too large to be explained by any known hadronic processes. This state of matter is not describable in terms of ordinary color-neutral hadrons, because there is no known self-consistent theory of matter composed of ordinary hadrons at th measured densities. The most economical description is in terms of the underlying quark and gluon degrees of freedom. Models taking this approach have scored impressive successes in explaining many, but not all, of the striking features measured to date. There is not yet irrefutable evidence that this state of matter is characterized by quark deconfinement or chiral symmetry restoration, which would be a direct indication of quark-gluon plasma formation. The anticipated program of additional incisive experimental measurements combined with continued refinement of the theoretical description is needed to achieve a complete understanding of the state of matter created at RHIC.
29-Oct-05 PANIC
PHOBOS White PaperPHOBOS White Paper
One of the most important discoveries at RHIC is the evidence that, in central Au+Au collisions at ultra-relativistic energies, an extremely high energy den- sity system is created, whose description in terms of simple hadronic degrees of freedom is inappropriate. Furthermore, the constituents of this system experience a significant level of interaction with each other inside the medium. These conclusions are based on very general and, to a large extent, model independent arguments. It is not claimed that the observed phenomena are unique to RHIC energies. Nor is it claimed that there is direct evidence in the data analyzed so far for color deconfinement or chiral symmetry restoration.
29-Oct-05 PANIC
STAR White PaperSTAR White Paper
The properties already delineated, with seminal contributions from STAR, point toward a dense, opaque, non-viscous, pre-hadronic liquid state that was not anticipated before RHIC. Determining whether the quarks and gluons in this matter reach thermal equilibrium with one another before they become confined within hadrons, and eventually whether chiral symmetry is restored, are two among many profound questions one may ask. Further elaboration of the properties of this matter, with eyes open to new unanticipated features, remains a vital research mission, independent of the answer that nature eventually divulges to the more limited question that has been the focus of this document.
29-Oct-05 PANIC
Perfect Fluid?Perfect Fluid? We sailed very close
to the wind with the Tampa press release: “RHIC Scientists
Serve up ‘Perfect Liquid’ ”
“While RHIC scientists don’t have a direct measure of viscosity, they can infer from the flow pattern that, qualitatively, the viscosity is very low, approaching the quantum mechanical limit. ”
REALLY ?
Absence of evidence is not Absence of evidence is not evidence of absence (C. evidence of absence (C. Sagan?)Sagan?)
Details that could throw Details that could throw doubt on your doubt on your interpretation must be interpretation must be given (R. Feynman)given (R. Feynman)
T. Hirano, PANIC05T. Hirano, PANIC05
29-Oct-05 PANIC
Physics Questions to be addressed by the Working Physics Questions to be addressed by the Working
GroupsGroups What is the nature of the phase transition between
nuclear matter and quark matter? (How does this type of matter return to its usual forms observed in our detectors?) How does hadronization work? Is there evidence for deconfinement?
How does the clearly evident thermodynamic character of a high energy heavy ion collision evolve from the zero entropy initial state? How does the collision thermalize so quickly?
What are the properties of strongly coupled quark gluon plasma? Transport properties? Medium properties: Resonant states? Collision probability? Screening length?
Is chiral symmetry restored? When in the collision and what are the effects?
What can non-equilibrium field theory tell us about: Initial state? Is there a color glass condensate? Thermalization? Medium properties?
What is the structure and dynamics inside the proton? What is the spin structure of the nucleon? Is parity violation important?
Are there exotic hadrons that can be studied at RHIC II?
29-Oct-05 PANIC
Strategy Leading to Strategy Leading to AnswersAnswers
Continue analysis of precision probes from existing (large) data sets.
Invest in near-term detector upgrade projects for PHENIX and STAR to take full advantage of the existing accelerator capabilities.
Invest in accelerator and detector R&D, in preparation for RHIC II, to enable crucial measurements of this new form of dense matter using rare probes
Construct Electron Beam Ion Source as quickly as possible to improve reliability and increase capabilities of the heavy-ion injection system and to realize projected reduction in RHIC operating costs.
29-Oct-05 PANIC
Continue analysis of
precision probes
29-Oct-05 PANIC
Precision ProbesPrecision Probes This one figure encodes
rigorous control of systematics
in four different measurements over many orders of magnitude
centralNcoll
= 975 94
== ==
29-Oct-05 PANIC
Continued Analysis of Precision Continued Analysis of Precision Probes?Probes?
What’s left? For starters:
True thermal photons: Elliptic flow of photons
“The observation of such an asymmetry would be a signature for the presence of a quark gluon plasma and would establish the importance of jet-plasma interactions as a source of electromagnetic radiation.”(S.Turbide, C. Gale, R.J. Fries, hep-ph/0508201)
Photon+jet +jet
coincidences~ 1nb / GeV atE ~ 15 GeV
Presently:~0.25 nb-1
recorded
✔✔✔✔??
XX
✔ ✔ Accessible in RHIC IAccessible in RHIC I
29-Oct-05 PANIC
Invest in near-term detector
upgrade projects
29-Oct-05 PANIC
Near-Term upgradesNear-Term upgrades STAR TOF:
underway 16 institutions
PHENIX HBD: underway 8 institutions
Vertex detectors PHENIX partially
underway STAR proposal
in preparation
jetjet
Tracking flavor in jet tomography
Thermal radiation, chiral
symmetry restoratio
n
Heavy quark flow
29-Oct-05 PANIC
Full Barrel Time-of-Flight system
DAQ and TPC-FEE upgrade
Forward Meson Spectrometer
Integrated Tracking Upgrade
HFT pixel detector
Barrel silicon tracker
Forward silicon tracker
Forward triple-GEM EEMC tracker
STAR UpgradesSTAR Upgrades
TPC
Magnet
Barrel EMC
End Cap EMCBeam-Beam Counters
Forward o Det.
Photon Mult. Det.
FTPC’s
VPD’s(TOF Start)
ZDC
29-Oct-05 PANIC
PHENIX UpgradesPHENIX Upgrades
endcap VTX 1.2 < < 2.7
barrel VTX | < 1.2
NCC 0.9 < < 3.0
Provides displaced vertex & jet measurement over ~2
GEM
NCC
VTX
GEM | < 0.7
HBD
29-Oct-05 PANIC
-3 -2 -1 0 1 2 3 rapidity
Prompt photons: central EMCal |y| < 0.35 forward NCC 0.9 < y < 3.0 (-3.0 < y <-0.9) Jet (charged): central TPC + VTX || < 1.2 forward silicon 1.2 < < 2.7 (-2.7 < <-1.2) Jet (energy): forward NCC 0.9 < < 3.5 (-3.5 < < -0.9)
cove
rage
2
Large acceptance for -jet tomography: expect measurements out to Ejet > 20 GeV
Large acceptance for flavor tagging Limited acceptance for p – meson separation
4 GeV
10GeV
29-Oct-05 PANIC
Invest in accelerator and detector R&D, in preparation for
RHIC II
29-Oct-05 PANIC
Physics Beyond the Reach of Current Physics Beyond the Reach of Current
FacilityFacility
High T QCD (AA, pA, and pp): Electromagnetic radiation (e+epair continuum) Heavy flavor (c- and b-production) Jet tomography (jet-jet and -jet) Quarkonium (J/, ’ , c and (1s),(2s),(3s))
Spin structure of the nucleon: Quark spin structure q/q (W-production) Gluon spin structure G/G (heavy flavor and -jet
correlations)
Low x phenomena gluon saturation in nuclei
(particle production at forward rapidity)
Provide key measurements so far inaccessible at RHIC in three broad areas:
requires highestAA luminosity
All measurements require upgrades of detectors and/or RHIC luminosity
29-Oct-05 PANIC
Jet TomographyJet Tomography Even with detailed
jet tomographyavailable to date:
There remain substantial uncertainties in extractingquantities as fundamental as
(U. Wiedemann, this conference)
Note that within these uncertainties,
Need a different (intrinsic) scale heavy flavor
Pion gas
Cold nuclear matter
RHIC data
sQGP
QGP
R. Baier, NPA 715 (2003) 209
4.0 < pTtrig < 6.0 GeV/cz
2.0 < pTassoc < pT(trig) GeV/c
0.15 < pTassoc < 4.0 GeV/c
2ˆˆ LqEq srad
3~~ˆ Tq
29-Oct-05 PANIC
Heavy FlavorHeavy Flavor All(?) length scales in the QCD plasma are “degenerate”:
i.e. they all are proportional to 1/T (times various powers of g)
Fix this by introducing heavy flavor: Mc ~ 1.3 GeV
Mb ~ 5.0 GeV
to introduce new scales 1 / Mc ~ 0.15 fm
1 / Mb ~ 0.04 fm Flavor tagged jets
Bohr radii (onium): J/ ~ 0.29 fm ~ 0.13 fm “Onium” spectroscopy
Completing these measurements require RHIC II luminosities
RHIC
29-Oct-05 PANIC
Current and Projected Current and Projected StatusStatus
Run-2 data set barely discriminates between enhanced and suppressed J/ production
Run-4 analysis distinguishes between ‘ordinary’ and ‘anamolous’ suppression
Full sensitivity to screening physics using J/ and ’ will require much greater integrated luminosities, such as those provided by x10 luminosity upgrade to RHIC
▐ Run 2Run 2
▐ Run 4Run 4
▐ RHIC RHIC IIII Coalescence
Model
29-Oct-05 PANIC
Heavy Flavor Tagged Jets in Heavy Flavor Tagged Jets in STARSTAR
Complete measurements possible only with RHIC II + Detector upgrades
These measurements require RHIC II luminosities
Ramona Vogt, hep-ph/0111271
p+p
pT ~ 15 GeV/c: (p+p) ~5 x 10-4 b/Gev (Au+Au) ~20b/Gev centrally produced But 5 years of RHIC I Au+Au (10 nb-1) needed 200K b-bar pairs
29-Oct-05 PANIC
SpinSpin The entire spin program is luminosity-starved: Original RHIC Spin proposal:
320 pb-1 , 70% polarization at 200 GeV (ALL for direct photons)
800 pb-1, 70% polarization at 500 GeV (AL for W’s) To date:
Polarization ~50% Integrated luminosity ~5 pb-1 Impressive achievements given the limited time for
machine development during the polarized proton running periods
Even if RHIC II did not improve p+p luminosity, it would allow more efficient progress through the heavy ion program.
Fortunately, gains are also expected from e-cooling(1.5 5.0) x 1032 cm-2 s-1
29-Oct-05 PANIC
p+Ap+A Another luminosity-starved
program: Run-3: 2.7 nb-1 d+Au
Provides clear J/ signals With modest discrimination power
to test shadowing models A clear indication of the much
greater x2 range made available by RHIC
A clear need for 20 nb-1 : shadowing 200 nb-1 : ’, Drell-Yan >200 nb-1 : ’s
Measurements beyond ~20 nb-
1 require RHIC II luminosities
29-Oct-05 PANIC
From RHIC I to RHIC IIFrom RHIC I to RHIC II Design Luminosity for Au+Au:
LD = 2 x 1026 cm2 s-1
Integrated (delivered) luminosity per week ~ 0.06 nb-1
Run-4 performance establishes 2 x LD in hand (for Au+Au)
Suggests “ultimate” RHIC I Au+Au run delivers 2-4 nb-
1
HoweverA. Many crucial characterization measurements
require well in excess of 10 nb-1
B. Full utilization of the facility requires that such samples and comparable p+p baseline d+Au control
be acquired as rapidly as efficiently as possible
Both “A” and “B” argue for RHIC II 40 x LD
29-Oct-05 PANIC
RHIC Upgrades RHIC Upgrades TimelineTimeline
~ 2008 (LHC start)
RHIC baseline program
Au-Au ~ 250 b-1 at 200 GeV Species scan at 200 GeV Au-Au energy scan Polarized protons 150 nb-
1
Full utilization of RHIC opportunities:
Studies of sQGP with rare probes: jet tomography, open flavor, J/, ’, c, (1s), (2s), (3s)
Complete spin physics programExploit p-A physics
Extended program with 1st detector upgrades:
Au-Au ~ 1.5 nb-1 at 200 GeVPolarized p 500 GeVStart p-A program
RHIC operation
Near term upgrades PHENIX: HBD, VTX STAR: DAQ, FMS, TOF
Longer term detector upgrades RHIC upgrades
Near term: Base line Longer term: Medium term:
RHIC luminosity upgrade
~ 2010-2012
eRHIC
29-Oct-05 PANIC
Construct Electron Beam Ion Source as
quickly as possible
29-Oct-05 PANIC
EBIS StatusEBIS Status EBIS Electron Beam Ion Source
Replaces tandems (thereby avoiding ~$9 M reliability investment)
Extends range of species (polarized 3He, noble elements, uranium)
Approved for construction CD-1 obtained $19.4M cost
($4.5M NASA) 3.5 yr schedule
FY06-09
New Physics!
(Next slide)
29-Oct-05 PANIC
U+U collisionsU+U collisions Static deformation provides a way to vary the
‘other’ control parameter (baryon chemical potential)
29-Oct-05 PANIC
Speaking of High Baryon Speaking of High Baryon DensityDensity
There is considerable uncertainty in the location of the QCD critical point
RHIC II might make major advances on the “other” QCD front: U+U beams High luminosity
(?) Comprehensive
detectors Superb control of
systematics when changing √s
Needs input RSN (W. Needs input RSN (W. Fischer)Fischer)
A feature of collidersA feature of colliders(an anti-feature of fixed (an anti-feature of fixed target)target)
29-Oct-05 PANIC
Not Covered HereNot Covered Here Spin prospects- especially as improved by
Detector upgrades Increased luminosity
(S. Vigdor)
Truly forward physics (see F. Videbaek, Nov-04)
pA/dA physics (C. Gagliardi)
Exotica Strong CP violation New physics via parity violating spin processes (e.g.,
ALPV )
Ultra-peripheral collisions
Relation to LHC (A. Frawley)
29-Oct-05 PANIC
How Do We Get There?How Do We Get There? My personal perspective (prejudices): “QCDLab” is too good of a descriptor to give up:
We should not surrender it to other facilities that lack a dedicated program any of the QCDLab components (polarized protons, A+A, p+A,
e+A)
The vision must be a comprehensive one that includes Continued enhancements to existing detectors/collaborations Continued improvements on RHIC luminosity Steady progress towards eRHIC
I do not believe that this picture, taking into account existing budgetary constraints, can accommodate a major new detector for RHIC.
I do believe that many of the appealing features of R2D can and should be considered as part of the eRHIC detector
29-Oct-05 PANIC
SummarySummary Continued program based on “major discovery potential”.
Already established, more to come Scientific merit
Evident in unparalleled quantitative precision in complex environment(s)
Connection to other fields and interest outside our field Established ties to gauge/string correspondence Establishing ties to ‘real’ plasma field Re-establishing(?) ties to early universe
Unique opportunity (science lost without this) To finish what we have started RHIC spin e-RHIC
Societal impact Broad international community Excellent PhD production and post-doc development Excellent record of job creation
Theory: 11 tenured (!), 4 untenured, 3 new appointments Experiment: 3 untenured, 1 new appointment
top related