updated status and plans of the phobos experiment
DESCRIPTION
Updated Status and Plans of the PHOBOS Experiment. Gunther Roland/MIT. Presentations to RHIC Planning Group and PAC 12/03 and 12/05 2003. Collaboration (Dec 2003). Birger Back, Mark Baker, Maarten Ballintijn, Donald Barton, Bruce Becker, Russell Betts, - PowerPoint PPT PresentationTRANSCRIPT
Updated Status and Plansof the
PHOBOS Experiment
Gunther Roland/MIT
Presentations to RHIC Planning Group and PAC
12/03 and 12/05 2003
Collaboration (Dec 2003)
Birger Back, Mark Baker, Maarten Ballintijn, Donald Barton, Bruce Becker, Russell Betts,
Abigail Bickley, Richard Bindel, Andrzej Budzanowski, Wit Busza (Spokesperson), Alan Carroll,
Patrick Decowski, Edmundo Garcia, Tomasz Gburek, Nigel George, Kristjan Gulbrandsen,
Stephen Gushue, Clive Halliwell, Joshua Hamblen, Adam Harrington, Conor Henderson,
David Hofman, Richard Hollis, Roman Holynski, Burt Holzman, Aneta Iordanova, Erik Johnson,
Jay Kane, Nazim Khan, Piotr Kulinich, Chia Ming Kuo, Jang Woo Lee, Willis Lin, Steven Manly,
Alice Mignerey, Gerrit van Nieuwenhuizen, Aaron Noell, Rachid Nouicer, Andrzej Olszewski,
Robert Pak, Inkyu Park, Heinz Pernegger, Corey Reed, Louis Remsberg, Christof Roland,
Gunther Roland, Joe Sagerer, Pradeep Sarin, Pawel Sawicki, Iouri Sedykh, Wojtek Skulski,
Chadd Smith, Peter Steinberg, George Stephans, Andrei Sukhanov, Ray Teng,
Marguerite Belt Tonjes, Adam Trzupek, Carla Vale, Robin Verdier, Gábor Veres, Bernard
Wadsworth, Frank Wolfs, Barbara Wosiek, Krzysztof Wozniak, Alan Wuosmaa, Bolek Wyslouch,
Jinlong Zhang
ARGONNE NATIONAL LABORATORY BROOKHAVEN NATIONAL LABORATORYINSTITUTE OF NUCLEAR PHYSICS, KRAKOW MASSACHUSETTS INSTITUTE OF TECHNOLOGYNATIONAL CENTRAL UNIVERSITY, TAIWAN UNIVERSITY OF ILLINOIS AT CHICAGO
UNIVERSITY OF MARYLAND UNIVERSITY OF ROCHESTER
PHOBOS Future
• Complete Baseline Program in the next 3-4 Runs
• Essential Items– Long Au+Au Run – Energy Scan (63 GeV + 1 addt’l Energy)– Species Scan (Cu+Cu + 1 addt’l Species)– p+p Reference Data
• Budget constraints link near-term and long-term RHIC running considerations
PHOBOS Status
2000 2001 2002 2003
5
10
15
~550 citations on SPIRES
Year
To
tal P
ub
licat
ion
s
Exponential Growth
RHIC Status
• Unique State of Matter formed in Au+Au– Very High Density– Equilibrated Strangeness production– Collective Behavior in Early Stage– Opaque to fast partons
• What are the initial conditions that lead to these properties?
• Systematic Study vs – Energy Density– System Size
– Rapidity, xf
• Data continue to surprise us
PHOBOS Detector 2004 (+beyond)
T0
T0
• Final Configuration
• Compared to Au+Au Run II:– 15x faster DAQ – 2.5x higher PID reach– new forward Proton Calorimeters– p+p, d+Au Spectrometer Trigger– SpecCal for high pT trigger in Au+Au
SpecCal
PHOBOS Capabilities: Multiplicity Array
QM’04 Preview
PHOBOS preliminary
h+ + h- Au-Au data
Phys. Rev. Lett. 91, 052303 (2003)
130 GeV: PRL 89:222301, 2002
PHOBOS Capabilities: Spectrometer
pT (GeV/c)0.05 0.5 5.0
Stoppingparticles
dE/dx ToF
Continuous Particle ID from low to high pT
QM’04 Previewp
K
Eloss (MeV)
dE
/dx
p (GeV) p (GeV)
PHOBOS Capabilities: Spectrometer
Acceptance forward of mid-rapidity: 0 < < 2.5
Spectrometer Acceptance
PHOBOS Future
• Complete Baseline Program in the next 3-4 Runs
• Essential Items– Long Au+Au Run – Energy Scan (63 GeV + 1 addt’l Energy)– Species Scan (Cu+Cu + 1 addt’l Species)– p+p Reference Data
• Budget constraints link near-term and long-term RHIC running considerations
PHOBOS Future
• Complete Baseline Program in the next 3-4 Runs
• Essential Items– Long Au+Au Run (Run IV)– Energy Scan (63 GeV + 1 addt’l Energy)– Species Scan (Cu+Cu + 1 addt’l Species)– p+p Reference Data
• Budget constraints link near-term and long-term RHIC running considerations
Crucial Link to d+Au!
must-do itemsin white paper
Comparison to Parton Saturation and RQMD Models
Parton saturation model prediction D. Kharzeev et al., hep-ph/0212316
Charged Hadron dN/d Distribution in d+Au
First result on d+Au min bias multiplicity
Many features reminiscent of lower energy p+A data
Important lessons for Saturation Model
nucl-ex/0311009 (subm.to PRL)
Comparison to Parton Saturation and RQMD ModelsCharged Hadron dN/d Distribution in d+Au
AMPT/HIJING close to data (-5.4 < < 4)
nucl-ex/0311009 (subm.to PRL)
Particle Ratios in d+Au: p/p vs Centrality
First particle ratio data from d+AuConstant p/p ratio vs centrality
Disagreement with expectations/models
nucl-ex/0309013 - submitted to PRC
Au+Au Phys. Rev. C 67, 021901R (2003)
d+Au pT Spectra
Phys. Rev. Lett. 91, 072302 (2003)
Au+Au
d+Au
RHIC d+Au/Au+Au results conclusively show that high pT suppression
at mid-rapidity is unique to Au+Au
?
??Exciting hints in d+Au
Need p+p reference data to fully
exploit existing d+Au
BRAHMS DNP’03 PreliminaryVitev, CIPANP’03
Scheduling Considerations
We considered 27wk/yr, 37wk/yr, 32wk/yr, 37wk/1.5yr, 54wk/2yr scenarios
54wk/2yr scenario not workable
Scheduling of energy/species scan early on critical for PHOBOS
Species Scan
• For many observables– rapid change from p+p to peripheral Au+Au
– large uncertainty in <Npart> for peripheral events
• Fe+Fe overlaps with well-measured <Npart> range in Au+Au
• AGS/SPS results on Si+Si vs Pb+Pb show violations of <Npart> scaling
Au+Au
Energy Scan
2x increase in particle density: Change from high-pT enhancement to strong suppression
SPS
RHIC
[ ]
[ ] [ ]
Energy Scan
NA49
AGS
PHENIX
Shape of excitation function between SPS and RHIC?
NA49, SQM’03
Summary
• PHOBOS/RHIC Data Set is expanding rapidly• Exciting (and puzzling) results in Au+Au and d+Au• Further insight from
– Energy Scan– Species Scan– p+p reference data
• Unique contributions from PHOBOS– Multiplicity Array– Spectrometer
• Very difficult scheduling – Timing of species/energy scans is crucial to fully exploit
PHOBOS (and RHIC) capabilities