Heavy flavor systematics from phenix
Sponsored Links
This presentation is the property of its rightful owner.
1 / 38

Heavy flavor systematics from PHENIX PowerPoint PPT Presentation

  • Uploaded on
  • Presentation posted in: General

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,…

Download Presentation

Heavy flavor systematics from PHENIX

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

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

  • 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

  • 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

  • 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) 


PT (GeV/c)

[email protected]

CNM IV: Forward, backward m from HF decay




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

Phys. Rev. C 88, 024906 (2013) 

Cronin peak: proton ~ > HFeWhy?

[email protected]

CNM II: d+Au heavy-flavor at 200 GeV

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

PT (GeV/c)

[email protected]

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]


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)


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?



Au-going, high-x

d-going, low-x

PT (GeV/c)

Phys. Rev. C 87, 034904 (2013)

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

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]

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

Interplay of two effects

CNM increases yield, competes with energy-loss suppression

[email protected]

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 forward y, Au+Au mid-rapidity


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

[email protected]

Additional lever arm: beam energy

charged hadrons from Au+Au

Phys. Rev. Lett. 109, 152301 (2012)  


pT (GeV/c)

Dominant energy-loss at high s

Transitions to stronger Cronin effect at lower s

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-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 v2at lower beam energy

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

[email protected]

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

Elastic + radiative energy loss

With running coupling a

[email protected]

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

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



Installed 2010-12




B e+X




p0 e+e-

[email protected]

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


Fit range:


[email protected]


VTX p+p results

FONLL consistent with b/(b+c) data

[email protected]


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]


    • 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]

    Backup slides

    [email protected]


    Eskola et al. JHEP 0904 (2009) 065

    [email protected]

    RAA of heavy-flavor: from RHIC to LHC

    Note to Craig add citations

    [email protected]

    [email protected]

    Charm production at 62 GeV reproduced by FONLL

    [email protected]

    [email protected]

    [email protected]

    Less bound charmonia in dAu collisions


    All three systems consistent within uncertainties

    [email protected]

    Less bound charmonia in dAu collisions


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

    Stronger effective breakup cross-section?

    [email protected]

    Photon in dA

    Phys.Lett. B718 (2012) 482-487

    [email protected]

  • Login