Education in the Physics and Astronomy DeptOn behalf of the PHENIX Collaboration
Heavy flavor systematics from PHENIX
Sep 27, 2013
Use systematics: spectra, elliptic flow,…
Present d+Au, Cu+Cu, excitation function,…
Which leads to the complexity of interpreting d+Au…
cogilvie@iastate.edu
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Sep 27, 2013
Likely largest impact at RHIC where spectra are softer
Possible collective effects
Final state energy-loss, absorption,….
Sep 27, 2013
Sep 27, 2013
RdA
Sep 27, 2013
Backward rapidity enhanced
or increase in <kT> due to initial scattering?
CNM III: Identified hadron spectra in dA
Sep 27, 2013
RdA
Sep 27, 2013
spectra = convolution of scattering + fragmentation
Or recombination effects in hadronization?
Or collective? Or…
Reasonable reproduction of p0
Vitev et al., PRD 74 (2006)
Phys.Lett. B718 (2012) 482-487 
Reasonable reproduction, misses centrality dependence
BUT, charm is enhanced at moderate pT
(non-photonic electrons RdA>1)
If not, then more effective suppression needed for J/y
PRL 107, 142301 (2011)
Normalize J/y by HF?
Charm is enhanced at moderate pt
(non-photonic electrons RdA>1)
Question, what axis? pT ?
Au-going, high-x
d-going, low-x
Sep 27, 2013
1) Enhancement in d+Au + energy-loss suppression in A+A
2) Models must attempt to reproduce both d+A and A+A
Min-bias collisions
Sep 27, 2013
Common suppression pattern when normalized by square of RdA
Does this take into account impact of initial state increase of <kT>?
Intermediate Cu+Cu: links d+A and Au+Au
Sep 27, 2013
d+Au to Cu+Cu to Au+Au
Sep 27, 2013
d+Au to Cu+Cu to Au+Au
Sep 27, 2013
dAu
Sep 27, 2013
cogilvie@iastate.edu
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Large uncertainties: Forward y in central d+Au ~ peripheral Cu+Cu
Cu+Cu forward y, Au+Au mid-rapidity
Additional lever arm: beam energy
Sep 27, 2013
Transitions to stronger Cronin effect at lower s
pT (GeV/c)
p0
Need RdA at lower-beam energy
Sep 27, 2013
How does RdA change from 200 GeV to 62 GeV
Three beam energies (62, 200 GeV, LHC) constrains interplay of structure function, initial state scattering
RdA calculations at 62 GeV
p RdA ~ 2 at 62 GeV
p RdA ~ 1.2 at 200 GeV
A. Accardi Eur. Phys. J. C 43, 121–125 (2005)
Non-photonic electrons Au+Au 62 GeV
Sep 27, 2013
Stronger CNM competing with weaker energy-loss
Forthcoming PHENIX publication
comparison with p+p, RAA etc.
If your model reproduces 200 GeV and 2.76 TeV heavy flavor RAA
Final call for 62 GeV HF RAA prediction
HF v2 at lower beam energy
Sep 27, 2013
HF flow is > 0 at 62 GeV, but uncertainties large
V2 2nd constraint on e-loss Au+Au 200 GeV
Sep 27, 2013
Many calculations, theory updates past few years
One example, P.B. Gossiaux SQM 2013
Sep 27, 2013
Sep 27, 2013
Suggestion in spirit of workshop,
This is being worked on for HF, but no results available yet
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Four layers in endcaps
Requires ~ 50 mm precision
Background components (left column)
Physics Goal
Progress on understanding many details
If a model reproduces a broad range of data
Can we infer any characteristics of QGP?
Either direct via a parameter of model
Diffusion parameter
Or run same dynamical model in a “box”, e.g. radiation + collision Eloss
Infer effective transport parameters
Which characteristics of sQGP are accessible this way and can we communicate this to our fellow physicists?
Maybe too many unsettled aspects yet
Summary
Levers: centrality, A, y, s, change impact of
Structure function, initial state scattering, e-loss,…
HF RdA enhancement up to factor of 1.5
Call for model calculations
Is dAu HF a better baseline for RAA HF and dAu J/y production??
Complexity of interpreting data from HI collisions
Cu+Cu HF yields smoothly connects dAu to Au+Au
Competition between enhancement + suppression
Change this competition
Au+Au HF data @ 62 GeV, need dAu running at 62 GeV
Backup slides
c-cbar
Eskola et al. JHEP 0904 (2009) 065
RAA of heavy-flavor: from RHIC to LHC
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y’ suppression stronger than J/y for more central dAu collisions
Stronger effective breakup cross-section?