Yale RHIG High p T Contributions
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Transcript of Yale RHIG High p T Contributions
Yale RHIG High pT Contributions
Boris Hippolyte: 1st year postdoc
Jon Gans: 5th year grad
Michael Miller: 5th year grad
Oana Catu : 2nd year grad
Christine Nattrass: beginning grad
John Harris: Physics Leader
September 2003 Mike Miller
What we’re doing now: PhysicsPhysics
•C. Adler et al.: Multiplicity distribution and spectra of negatively charged hadrons in Au+Au collisions at sqrt(s_NN)=130 GeV; Phys. Rev. Lett. (87), 112303 (2001)
•C. Adler et al.: Centrality Dependence of High pT Hadron Suppression in Au+Au collisions at sqrt(s_NN)=130 GeV; Phys. Rev. Lett. 89, 202301 (2002) nucl-ex/0206011.
•C. Adler et al.: Disappearance of back-to-back high pT hadron correlations in central Au+Au collisions at sqrt(s_NN)=200 GeV; Phys. Rev. Lett. 90, 082302 (2003)
•J. Adams et al: Evidence from d+Au measurements for final-state suppression of high pT
hadrons in Au+Au collisions at RHIC; Phys. Rev. Lett. 91, 072304 (2003)
•J. Adams et al., Transverse momentum and collision energy dependence of high pT hadron suppression in Au+Au collisions, submitted to Phys. Rev. Lett.
•J. Adams et al., Multi-Strange Baryon Production in Au+Au collisions at sqrt(s_NN)=130 GeV, submitted to Phys. Rev. Lett.
•M.L. Miller and R. J. Snellings: Understanding the effect of Geometry Fluctuations on High pT Elliptic Flow Measurements at RHIC; To be submitted to Phy. Rev. Lett.
Yale RHIG primary authored high pT papers
2002-2003: 11 invited and 5 contributed high-2002-2003: 11 invited and 5 contributed high-ppTT presentations presentations (Gans, Hippolyte, Miller)(Gans, Hippolyte, Miller)
September 2003 Mike Miller
Why Jets? Energy Loss in Dense Matter
Strong dependence of energy loss on gluon density glue• measure measure gluon density at early hot, dense phase Deconfined quarks and gluonsDeconfined quarks and gluons
Thick plasma (Baier et al.):
glueSglue
Debye
sRBDMS
q
vLqC
E
2
2
ˆ
~ˆ4
L
ELogrdCE jet
glueSRGLV 23 2
,
Thin plasma (Gyulassy et al.):
Gluon Bremsstrahlung
September 2003 Mike Miller
Yale High pT Focus
•Identified particle yields: pion, kaon, proton spectra with RICH detector (B. Hippolyte)
•Inclusive charged particle yields: h++h- spectra (J. Gans)
•2-particle high pT hadron correlations: jet, di-jet structure and yields (M. Miller, O. Catu, C. Nattrass)
•Topological Jet ID: tagged jet, di-jet spectra. (Identified particle) Fragmentation function measurements (all)
Show all in 15 minutes? No chance!Show all in 15 minutes? No chance!
September 2003 Mike Miller
Identified Hadron Spectra from RICH
Chemical propertiesChemical properties: temperature, chemical potential, flow: temperature, chemical potential, flowSoft vs. Hard PhysicsSoft vs. Hard Physics: Sensitive to gg, qg, qq contributions: Sensitive to gg, qg, qq contributions
September 2003 Mike Miller
Identified Hadron Spectra from RICH
Chemical propertiesChemical properties: temperature, chemical potential, flow: temperature, chemical potential, flowSoft vs. Hard PhysicsSoft vs. Hard Physics: Sensitive to gg, qg, qq contributions: Sensitive to gg, qg, qq contributions
September 2003 Mike Miller
200 GeV Charged Hadron Spectra
p+p spectrum: first at 200 GeV
High event rate, backgrounds vertexing bias => Problems solved by J. Gans
p+p: absolutely normalized
Methods/solutions applicable in d+Au
September 2003 Mike Miller
1
10-1
s 200 GeV
STAR Preliminary
Charged RAA: Comparison to Theory
collisions
AuAuRatio
N pp
pQCD:Vitev and Gyulassy, PRL 89, 252301 XN Wang, to be published (see also nucl-th/0302007
pQCD: good agreement; gluon density ~15 x cold nuclear matterpQCD: good agreement; gluon density ~15 x cold nuclear matter
No E-LossNo E-Loss
E-LossE-Loss
September 2003 Mike Miller
Charged RdAu: Turning off Final State
collisions
dAuRatio
N pp
High High ppTT Suppression is a Final State Effect! Suppression is a Final State Effect!
No suppression for minimum bias d+AuNo suppression for central d+AuWhat’s happening At pT>8 GeV/c?
Jon’s Thesis Cover
September 2003 Mike Miller
First Observation of Jets at RHIC
trigger
Near Side Far Side
s=200 GeV p+p
Can find this…
In this…
September 2003 Mike Miller
Jets In Most Violent CollisionsAdams et al., Phys.Rev.Lett. (91):072304,2003
“Near side” jet identical! pp=dAuAuAu
Disappearance of away-side jet is a Final State Disappearance of away-side jet is a Final State Effect!Effect! Jet Quenching Jet Quenching
Background subtracted
s=200 GeV
Mike’s Thesis Cover
September 2003 Mike Miller
Where are we? Where to go? Jets at RHIC are now well
established, excellent probe of medium
Produce strongly interacting, highly opaque matter
High pT suppression is most likely post-hard scattering phenomenon
Tagged jet fragmentation: distinguish hadronic vs. partonic E-
Loss Jet triggered data in p+p, d+Au (Oana
and Christine in progress)
September 2003 Mike Miller
Yale Contributions to STAR High pT
• New global reco software (Miller)
• RICH Reco (Hippolyte)• New V0 reco software (Betty,
Caines, Hippolyte)• Database and calibrations
(Gans)• Vertexing software (Gans,
Miller)• Jet finding software (Miller)• SVT Software (Betty, Caines,
Salur)
• SVT hardware (Caines)
• STAR II Hardware (Smirnov)
• Forward Tracking upgrade (Smirnov, Miller/MIT)
SoftwareSoftware HardwareHardware