Nov 2001 Craig Ogilvie 1 Angular Correlations at High pt: Craig Ogilvie for the Phenix Collaboration Energy-loss: increased medium-induced gluon-radiation hadron distribution softened, broadened? hard-scattered parton during Au+Au hard-scattered parton from e.g. p+p luon radiation cone of hadrons p p
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Angular Correlations at High pt: Craig Ogilvie for the Phenix Collaboration
hard-scattered parton from e.g. p+p. cone of hadrons. gluon radiation. p. p. Angular Correlations at High pt: Craig Ogilvie for the Phenix Collaboration. hard-scattered parton during Au+Au. hadron distribution softened, broadened?. Energy-loss: increased medium-induced - PowerPoint PPT Presentation
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Nov 2001 Craig Ogilvie 1
Angular Correlations at High pt:Craig Ogilvie for the Phenix Collaboration
Energy-loss:increased medium-induced
gluon-radiation
hadron distributionsoftened, broadened?
hard-scatteredparton during Au+Au
hard-scatteredparton from e.g. p+p
gluon radiation
cone of hadrons
p p
Nov 2001 Craig Ogilvie 2
Correlations
2-particle angular correlation functions
Medium-induced gluon emission within QGP – predicted to be broad angles (>10 deg shown later in talk)– fragmentation angular-width may be broader – correlations at small may be broadened
study correlations from peripheral => central reactions– complementary to single-particle pt spectra and +hadron
back-to-back correlations.
)(N
)(N)C(
events mixed
real
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Nov 2001 Craig Ogilvie 3
Outline
Examples of angular correlation data from p+p, e+p Angle correlations from Au+Au at s1/2 = 130 AGeV
– pt dependence – centrality dependence
Simulations of possible sources of angular correlations – work in progress
Measurements for this year-2 Which observable makes a link between experiment and theory
Nov 2001 Craig Ogilvie 4
ISR Data p+p s1/2 = 62 GeV
CCOR Collaboration (M. J. Tannenbaum) Trigger particle (neutral) with pt > 7.0 GeV/c
– azimuthal distribution of charged particles– strong back-to-back and near-side emission
back-to-backnear-side
Nov 2001 Craig Ogilvie 5
Transverse Momentum Within Jet
jT transverse momentum with respect to “jet” axis
Trigger PTjTJet JetPT jT
PoutkT
<| jT|> = 400 MeV/c, use as one check for what we observe in HI
CCOR CollaborationPhys. Lett. 97B, 163 (1980))
Nov 2001 Craig Ogilvie 6
HERA e+p Angular Distribution Within a Jet
Within a jet Yield of two particles
separated by angle 12
Transformed to
)/)sin(ln()/ln( 12
coneAngleP
coneAngle
Yield peaked atsmall 12 ,
More complicated variablechosen to match expt. with what can be calculated.
Nov 2001 Craig Ogilvie 7
Au+Au s1/2 = 130 AGeV
1.5M events, summer 2000 Phenix data -20 < collision vertex < 20 cm Central arm tracks