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Heavy flavor systematics from PHENIX. Craig Ogilvie, Iowa State University On behalf of the PHENIX Collaboration. Complexity of interpreting data from HI collisions Use systematics: spectra, elliptic flow,… Present d+Au, Cu+Cu, excitation function,…

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heavy flavor systematics from phenix

Heavy flavor systematics from PHENIX

Craig Ogilvie, Iowa State University

On behalf of the PHENIX Collaboration

  • 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…

[email protected]

complexity of d p a collisions
Complexity of d(p)+A collisions
  • Nuclear structure functions
    • Shadowing, saturation at low-x
    • Anti-shadowing at moderate, high-x
  • Initial state scattering
    • Often modeled as increase in effective kT
    • Likely largest impact at RHIC where spectra are softer
  • Possible collective effects
    • Barbara Jacak’s talk on Wed
  • Final state energy-loss, absorption,….
  • Centrality classification

[email protected]

cnm i d au heavy flavor at 200 gev
CNM I: d+Au heavy-flavor at 200 GeV
  • Non-photonic e, from heavy-flavor decays

Phys. Rev. Lett. 109, 242301 (2012) , 

  • Significant enhancement
  • at moderate pT

[email protected]

cnm ii d au heavy flavor at 200 gev
CNM II: d+Au heavy-flavor at 200 GeV
  • Non-photonic e, from heavy-flavor decays
  • Enhancement present in min-bias
  • Effect not caused by challenges of centrality definition

Phys. Rev. Lett. 109, 242301 (2012) 

RdA

PT (GeV/c)

[email protected]

cnm iv forward backward m from hf decay
CNM IV: Forward, backward m from HF decay

m

m

e

Forward rapidity suppressed

Likely shadowing at low-x in Au

Backward rapidity enhanced

anti-shadowing at higher x in Au?

or increase in <kT> due to initial scattering?

[email protected]

cnm iii identified hadron spectra in da
CNM III: Identified hadron spectra in dA

Phys. Rev. C 88, 024906 (2013) 

Cronin peak: proton ~ > HFeWhy?

[email protected]

cnm ii d au heavy flavor at 200 gev1
CNM II: d+Au heavy-flavor at 200 GeV

Phys. Rev. Lett. 109, 242301 (2012) 

RdA

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

PT (GeV/c)

[email protected]

example with p 0 r da
Example with p0RdA
  • p0calc from I. Vitev
  • Reasonable reproduction of p0
    • Nuclear structure function
    • Cronin
      • 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 

[email protected].edu

j y cnm
J/y CNM

EPS09 nuclear structure functions plus breakup

Reasonable reproduction, misses centrality dependence

BUT, charm is enhanced at moderate pT

(non-photonic electrons RdA>1)

Do these calculations reproduce open charm RdA >1 ?

If not, then more effective suppression needed for J/y

PRL 107, 142301 (2011)

y

normalize j y by hf
Normalize J/y by HF?
  • J/yat 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

J/y

Au-going, high-x

d-going, low-x

PT (GeV/c)

Phys. Rev. C 87, 034904 (2013)

connect d au to a a
Connect d+Au to A+A

Phys. Rev. Lett. 109, 242301 (2012) , 

Min-bias collisions

1) Enhancement in d+Au + energy-loss suppression in A+A

2) Models must attempt to reproduce both d+A and A+A

[email protected]

one method to organize results
One method to organize results

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>?

[email protected]

i ntermediate cu cu links d a and au au
Intermediate Cu+Cu: links d+A and Au+Au

Peripheral Cu+Cu (yellow)

Enhancement ~ central d+Au (blue)

[email protected]

d au to cu cu to au au
d+Au to Cu+Cu to Au+Au

Interplay of two effects

CNM increases yield, competes with energy-loss suppression

[email protected]

d au to cu cu to au au1
d+Au to Cu+Cu to Au+Au

Higher pT

CNM increases yield, stronger energy-loss suppression

[email protected]

cu cu heavy flavor forward rapidity
Cu+Cu heavy-flavor, forward rapidity

Cu+Cu forward y, Au+Au mid-rapidity

dAu

Large uncertainties: Forward y in central d+Au ~ peripheral Cu+Cu

[email protected]

additional lever arm beam energy
Additional lever arm: beam energy

charged hadrons from Au+Au

Phys. Rev. Lett. 109, 152301 (2012)  

p0

pT (GeV/c)

Dominant energy-loss at high s

Transitions to stronger Cronin effect at lower s

need r da at lower beam energy
Need RdA at lower-beam energy
  • 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 scattering
  • RdAcalculations at 62 GeV
    • pRdA ~ 2 at 62 GeV
    • pRdA ~ 1.2 at 200 GeV

A. AccardiEur. Phys. J. C 43, 121–125 (2005)

[email protected]

non photonic electrons au au 62 gev
Non-photonicelectrons Au+Au 62 GeV

Lower beam energy changes interplay of two effects

Stronger CNM competing with weaker energy-loss

Forthcoming PHENIX publication

spectra with smaller systematics

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 v 2 at lower beam energy
HF v2at lower beam energy

HF flow is > 0 at 62 GeV, but uncertainties large

[email protected]

v 2 2 nd constraint on e loss au au 200 gev
V2 2nd constraint on e-loss Au+Au 200 GeV
  • Low-pt Charm v2, extent of thermalization of HF
  • Challenge for theory to reproduce both RAA, v2

Many calculations, theory updatespast few years

[email protected]

one example p b gossiaux sqm 2013
One example, P.B. Gossiaux SQM 2013

Elastic + radiative energy loss

With running coupling a

[email protected]

is d pt pt what we should be plotting for hf
Is dpT/pT what we should be plotting for HF?

PRC 87, 034911 (2013)

Suggestion in spirit of workshop,

This is being worked on for HF, but no results available yet

[email protected]

vtx upgrade @ phenix
VTX Upgrade @ PHENIX

Two layers of silicon pixel detectors

Two layers of silicon strip detectors

Four layers in endcaps

Tracks extrapolate back to collision vertex

Displaced vertices  charm (D), beauty (B)

Requires ~ 50 mm precision

e

X

Installed 2010-12

De+X

Au

Au

B e+X

e

X

e

p0 e+e-

[email protected]

vtx p p results
VTX p+p results
  • DCA data are fit by expected DCA shapes of
    • Signal components : c  e and b  e (right column)
    • Background components (left column)

charm/bottom assumes PYTHIA spectra

b/(b+c)=0.22+-0.06

Fit range:

0.2<|DCA|<1.5(mm)

[email protected]

2012/10/23

vtx p p results1
VTX p+p results

FONLL consistent with b/(b+c) data

[email protected]

2012/10/23

physics goal
Physics Goal

Energy-loss heavy-flavor  understand nature of sQGP

    • 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

[email protected]

summary
Summary
  • Complexity of interpreting d+Au
    • Levers: centrality, A, y, s, change impact of
      • Structure function, initial state scattering, e-loss,…
    • HF RdAenhancement 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 dAuto Au+Au
      • Competition between enhancement + suppression
    • Change this competition
      • Au+Au HF data @ 62 GeV, need dAu running at 62 GeV

[email protected]

x ranges
X-ranges

Eskola et al. JHEP 0904 (2009) 065

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less bound charmonia in dau collisions
Less bound charmonia in dAu collisions

arXiv:1305.5516

All three systems consistent within uncertainties

[email protected]

less bound charmonia in dau collisions1
Less bound charmonia in dAu collisions

arXiv:1305.5516

y’ suppression stronger than J/y for more central dAu collisions

Stronger effective breakup cross-section?

[email protected]

photon in da
Photon in dA

Phys.Lett. B718 (2012) 482-487

[email protected]

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