Craig Ogilvie, Iowa State University On behalf of the PHENIX Collaboration Heavy flavor systematics from PHENIX Sep 27, 2013 1 • Complexity of interpreting data from HI collisions • Use systematics: spectra, elliptic flow,… • Present d+Au, Cu+Cu, excitation function,… [email protected]
Craig Ogilvie, Iowa State University On behalf of the PHENIX Collaboration Heavy flavor systematics…
Jan 20, 2018
CNM I: d+Au heavy-flavor at 200 GeV Sep 27, Non-photonic e, from heavy-flavor decays Phys. Rev. Lett. 109, (2012), Phys. Rev. Lett. 109, (2012) Significant enhancement at moderate p T
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Craig Ogilvie, Iowa State UniversityOn behalf of the PHENIX Collaboration
Heavy flavor systematics from PHENIX
Sep 27, 20131
• Complexity of interpreting data from HI collisions• Use systematics: spectra, elliptic flow,…• Present d+Au, Cu+Cu, excitation function,…
• Which leads to the complexity of interpreting d+Au…
Complexity of d(p)+A collisions
Sep 27, 20132
Nuclear structure functionsShadowing, saturation at low-xAnti-shadowing at moderate, high-x
Initial state scatteringOften modeled as increase in effective kTLikely largest impact at RHIC where spectra are softer
Possible collective effectsBarbara Jacak’s talk on Wed
Final state energy-loss, absorption,….Centrality classification
CNM I: d+Au heavy-flavor at 200 GeV
Sep 27, 20133
Non-photonic e, from heavy-flavor decays Phys. Rev. Lett. 109, 242301 (2012) , Significant enhancement
at moderate pT
CNM II: d+Au heavy-flavor at 200 GeV
Sep 27, 20134
Non-photonic e, from heavy-flavor decays
Phys. Rev. Lett. 109, 242301 (2012)
Enhancement present in min-biasEffect not caused by challenges of centrality definition
RdA
PT (GeV/c)
CNM IV: Forward, backward m from HF decay
Sep 27, 20135
m me
Forward rapidity suppressedLikely shadowing at low-x in Au
Backward rapidity enhancedanti-shadowing at higher x in Au?or increase in <kT> due to initial scattering?
CNM III: Identified hadron spectra in dA
Sep 27, 20136
Phys. Rev. C 88, 024906 (2013)
Cronin peak: proton ~ > HFe
Why?
RdA
PT (GeV/c)
CNM II: d+Au heavy-flavor at 200 GeV
Sep 27, 20137
Phys. Rev. Lett. 109, 242301 (2012)
Does <kT> increase have larger impact when p+p spectrum is soft?spectra = convolution of scattering + fragmentation
Or recombination effects in hadronization? Or collective? Or…Opportunity for theory impact
Example with p0 RdA
Sep 27, 20138
p0 calc from I. VitevReasonable reproduction of p0
Nuclear structure functionCronin
Large initial state multiple-scattering
Final state Eloss Need calculations for heavy-
flavor RdA
Vitev et al., PRD 74 (2006)Phys.Lett. B718 (2012) 482-487
J/y CNM
Sep 27, 20139 y
EPS09 nuclear structure functions plus breakupReasonable reproduction, misses centrality dependence
BUT, charm is enhanced at moderate pT
(non-photonic electrons RdA>1)
1) Do these calculations reproduce open charm RdA >1 ?
2) If not, then more effective suppression needed for J/y
PRL 107, 142301 (2011)
Normalize J/y by HF?
Sep 27, 201310
J/y at mid-y suppressed @low-pt
Charm is enhanced at moderate pt (non-photonic electrons RdA>1)
Alternative: use dA HF spectra as baseline?
• Question, what axis? pT ?RdA
PT (GeV/c)
J/y
Phys. Rev. C 87, 034904 (2013)
Au-going, high-x
d-going, low-x
Connect d+Au to A+A
Sep 27, 201311
Phys. Rev. Lett. 109, 242301 (2012) ,
1) Enhancement in d+Au + energy-loss suppression in A+A2) Models must attempt to reproduce both d+A and A+A
Min-bias collisions
One method to organize results
Sep 27, 201312
Phys. Rev. Lett. 109, 242301 (2012) , Matt Durham
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, 201313
Peripheral Cu+Cu (yellow)Enhancement ~ central d+Au (blue)
d+Au to Cu+Cu to Au+Au
Sep 27, 201314
Interplay of two effectsCNM increases yield, competes with energy-loss suppression
d+Au to Cu+Cu to Au+Au
Sep 27, 201315
Higher pTCNM increases yield, stronger energy-loss suppression
dAu
Cu+Cu heavy-flavor, forward rapidity
Sep 27, 201316
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, 201317
Dominant energy-loss at high s Transitions to stronger Cronin effect at lower s
pT (GeV/c)
charged hadrons from Au+Aup0 Phys. Rev. Lett. 109, 152301 (2012)
Need RdA at lower-beam energy
Sep 27, 201318
Not in current RHIC running plan :(How does RdA change from 200 GeV to 62 GeV Three beam energies (62, 200 GeV, LHC) constrains interplay
of structure function, initial state scatteringRdA 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, 201319
Lower beam energy changes interplay of two effectsStronger CNM competing with weaker energy-loss
Forthcoming PHENIX publicationspectra with smaller systematicscomparison 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, 201320
HF flow is > 0 at 62 GeV, but uncertainties large
V2 2nd constraint on e-loss Au+Au 200 GeV
Sep 27, 201321
Low-pt Charm v2, extent of thermalization of HFChallenge for theory to reproduce both RAA, v2
Many calculations, theory updates past few years
One example, P.B. Gossiaux SQM 2013
Sep 27, 201322
Elastic + radiative energy lossWith running coupling a
Is dpT/pT what we should be plotting for HF?
Sep 27, 201323
PRC 87, 034911 (2013)
Suggestion in spirit of workshop, This is being worked on for HF, but no results available yet
VTX Upgrade @ PHENIXTwo layers of silicon pixel detectorsTwo layers of silicon strip detectorsFour layers in endcapsTracks extrapolate back to collision vertexDisplaced vertices charm (D), beauty (B)Requires ~ 50 mm precision
De+X Au
e
Au
X
B e+X
Xp0 e+e- ee
Sep 27, 201324
Installed 2010-12
VTX p+p results
Sep 27, 201325 2012/10/23
charm/bottom assumes PYTHIA spectra
DCA data are fit by expected DCA shapes of • Signal components : c e and b e (right column)• Background components (left column)
Fit range : 0.2<|DCA|<1.5(mm)
b/(b+c)=0.22+-0.06
Physics Goal
Sep 27, 201327
Energy-loss heavy-flavor understand nature of sQGPProgress on understanding many detailsIf a model reproduces a broad range of data
Can we infer any characteristics of QGP?Either direct via a parameter of model
Diffusion parameterOr run same dynamical model in a “box”, e.g. radiation +
collision Eloss
Infer effective transport parametersWhich characteristics of sQGP are accessible this way and can we
communicate this to our fellow physicists?Maybe too many unsettled aspects yet
Summary
Sep 27, 201328
Complexity of interpreting d+AuLevers: 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 calculationsIs 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+AuCompetition between enhancement + suppression
Change this competitionAu+Au HF data @ 62 GeV, need dAu running at 62 GeV
X-ranges
Sep 27, 201330
SPSPb+Pb17 GeV
RHIC Au+Au200 GeV
LHC Pb+Pb5.5 TeV
c-cbar X~10-1 X~10-2 X~10-3 to 10 -4
Eskola et al. JHEP 0904 (2009) 065
[email protected] Sep 27, 201332
[email protected] Sep 27, 201334
[email protected] Sep 27, 201335
Less bound charmonia in dAu collisions
Sep 27, 201336
arXiv:1305.5516
All three systems consistent within uncertainties
Less bound charmonia in dAu collisions
Sep 27, 201337
arXiv:1305.5516
y’ suppression stronger than J/y for more central dAu collisionsStronger effective breakup cross-section?
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