overview of heavy flavor v 2

30/Mar/2006, SQM, UCLA ShinIchi Esumi, Univ. of Tsukuba 1

Overview of heavy flavor v2

ShinIchi Esumi, Inst. of Physics Univ. of Tsukuba

(1) RAA and v2 of various particle species meson/baryon and hadron/photon hydro-collective flow and recombination (2) Heavy flavor electron measurements non-photonic electron RAA, pT slope, v2

charm quark collectivity (radial/elliptic)(3) Future single muon v2, D v2, J/ v2

STAR/PHENIX upgrade

I. Choi, W. Dong, M. Issah, R. Lacey, H. Masui, S. Sakai, N. Xu, Z. Xu, Y. Zhang


Nuclear modification factor : RAA, RCP

direct photon

hadrons

baryons

mesons

(1) suppression of hadrons in Au+Au collisions at RHIC with respect to binary N-N collision scaling(2) baryon vs meson difference(3) no suppression in direct photon

RAA=yieldAA/(yieldpp*Ncoll_AA)RCP=(yieldcent/Ncoll_cent)/(yieldperi/Ncoll_peri)


0.0

0.1

0.2

v2

Elliptic event anisotropy : v2

R * v2(dire. )R = N

incl. / Nhadronic

baryons

mesons

(3) The measurement (smaller v2) favors prompt photon production for dominant source of direct photon.

(1) hydro-like mass ordering(2) baryon/meson ordering in hadron v2

Phys. Rev. Lett. 96, 032302 (2006)

N


quar

k nu

mbe

r sc

aled

v2

orig

inal

had

ron

v 2

KET = mT – mass (hadron)

mT + nquark scaling of v2

nquark scaling alone

mT scaling alone

mT + nquark scaling

WWND 2006, M. Issah

mass

mT s

lop

e

A+A

p+p

radial flow


Hydro-trend at low pT & quark recombination at mid pT

This mT + nquark scaling includes both hydro-trend and quark recombination, therefore it’s not really new. It gives a good description of large sets of data for wider pT region 　 (low-pT to mid-pT), but fails at higher pT.

v2

pT (GeV/c) S

STAR preliminary0-80% Au+Au 200GeVYan Lu SQM05P. Sorensen SQM05M. Oldenburg QM05

PHENIX preliminary0-93% Au+Au 200GeVH. Masui QM05

mT + nquark scaling

mT + nquark scaling


Quark recombination needed also for J/ data…

no recombination

no recombination


Early freeze-out for and J/, but still flows

Compiled by N. Xu, SQM 2006PHENIX (, K, p, J/): PRC69, 034909(04), QM05; STAR (, , ): QM05

SPS SPS

RHIC

a hint for non-zero radial flow of J/ in early hadronic stage or flow of charm quark in late QGP phase


Semi-leptonic decay of open-charm

Ne : inclusive electron yield

material amounts : 0

1.1% 1.7%

Dalitz : 0.8% X0 equivalent

0

With converterConversion in converter

W/O converter

0.8%

Non-photonic

Conversion from known material

? %

Photonic

cocktail method

converter method


Non-suppressed total charm yield (lower pT)

Non-suppressed charm yield at low pT : they are initially produced and survived until the end, did they interact with the produced hot matter?

We do not know the answer, that’s why we also measure their v2 and pT slope.


Radial flow of charm quark Yifei Zhang

AuAu Central charm hadron

AuAu Central , K, p

AuAu Central strangeness

hadron

another hint for non-zero radial flow of D-meson or flow of charm quark!?

Brast-wave fit to D-meson and single electron and muon from D-meson decay spectra


Run04: X=0.4%

Run02: X=1.3%

Non-pho./pho.

inclusive e v2

photonic e v2

line : estimated with 0 v2

measurement and simulation

e v2 without converter

Inclusive electron v2 and photonic contribution

Estimation of photonic electron v2 :decay kinematics simulation and/or experimental determination via with/without converter measurement.

Ratio of non-photonic over photonic electron yields (which is S/N) should be given in order to extract non-photonic electron v2.

e v2 with converter to enhance photonic electron yield


Extracted non-photonic electron v2

coalescence model prediction.with/without charm quark flowGreco, Ko, Rapp: PLB 595 (2004) 202

v2incl. =

Nnon-ph. v2non-ph. + Nphot. v2

phot.

Nnon-ph. + Nphot.

the 3rd hint for non-zero elliptic flow of charm quark!?


PHENIX preliminary data

(1) different v2(pt) shape assumptions for D meson (2) pT distribution by pythia tuned to reproduce electron spectra at 130GeV Au+Au(3) 2 restricted up to pT<2GeV/c

2 test with one free amplitude parameter : v2 = A * f(pT)

Extraction of D meson v2 Shingo Sakai

Minimum data are plottedfor each assumption

electron v2 fromD meson decay

D meson v2

D meson v2

D meson v2 : between and d

massD meson ~ massdeuteron


u/d/(s) quarks v2

mass effect in number of quark scaling

v2meson (pT) = v21 (R1 pT) + v22 (R2 pT) Ri = mi / mM

(mi : effective mass of quark i)

(Phys.Rev. C68 (2003) 044901 Zi-wei & Dence Molnar)

v2π(pT) ~ 2*v2q(1/2pT) v2D(pT) ~ v2u (1/6*pT) + v2c (5/6*pT)

c quark v2

0 0

Extraction of charm quark v2 Shingo Sakai

quark pT (GeV/c)

qua

rk v

2

Different shape assumptions for D meson v2 are propagated from the previous page in order to extract charm quark v2, the same minimum data are chosen again for each assumption.

Shingo preliminary

B. Zhang et al., nucl-th/0502056


v2D = v2

B : flat or decreasing

D e

B e (v2

B : flat at high pT)

B e (v2B : decreasing at high pT)

pT (GeV/c)

v 2

pT

Electron v2 from B meson Shingo Sakai

If B meson decay dominates non-photonic electron yield (RBD ~ 1) already at 2~3GeV/c (unlikely?), v2

B could be as large as v2D.

Otherwise, v2B should be smaller.

RBD measurement will be crucial.

1

0

Nelec.D + Nelec.

B

Nelec.B

to be determinedExperimentally

RBD =

RBD


Electron v2 analysis in STAR Weijiang Dong

dE/dx in TPC

Shower shape in EMC

Momentum in TPC vs. Energy in EMC

Conversion and dalitz rejection with minv.

The detector material in STAR caused too much photonic background, which caused huge systematic and statistical uncertainties. Our result is not sensitive enough to make any conclusion about heavy quark v2 so far. More work ahead! --- Weijiang, 8/Dec/2005


J/ v2, D v2, single muon v2

prompt muon ~ few %

pun.-thr. had ~ few %

decay muon> 90%

z-vertex position

nu

mb

er o

f fu

ll t

rack

trackeridentifier absorber

collision vertex rangeprompt muon

decay muon

punch-through hadron

stopped hadron

99% hadron absorbed

We only need high statistics for D, J/ v2.

Hadron measurement in muon arm is “easy”. We look for a few % prompt muon signal out of fully reconstructed tracks

~ 800(ee) + ~ 5000() J/s from full run4 200GeV Au+Au

Ihnjea Choi


R=50mm

R=180mm

R=330mm

R=50mm

R=180mm

R=330mm

A new reaction plane detector (1~||~2.5, cos2~ 0.7, Pb converter + scintillator) in PHENIX this summer 2006

Future upgrade of STAR/PHENIX detectors

Heavy Flavor Tracker for STAR

Vertex Vertex Tracker, Tracker, Forward Forward

Calorimeter Calorimeter for PHENIXfor PHENIX

PHENIXPHENIXmuon armmuon arm


Thank you very much!

(1) RAA and v2 of various particle species meson/baryon and hadron/photon hydro-collective flow and recombination (2) Heavy flavor electron measurements non-photonic electron RAA, pT slope, v2

charm quark collectivity (radial/elliptic)(3) Future single muon v2, D v2, J/ v2

STAR/PHENIX upgrade


inclusive and 0 v2

nucl-ex/0508019

v2 of direct photon gives complimentary information in understanding the origin of binary scaled direct photon production.

Bresmsrahlung, because of largerenergy loss v2 < 0

fragmentation

in vacuum, from escapedpartonv2 > 0


try to extract direct v2

v2direct =

R v2inclusive – v2

b.g.

R – 1

v2b.g. : expected v2 from hadronic decays

if v2direct = 0 R =

v2inclusive

v2b.g

nucl-ex/0508019


QM05 : Phenix preliminary run4inclusive and 0 v2

0

inclusive

v2

0 5 pT (GeV/c) 10

0-10 % 10-20 %

30-40 %

50-60 %40-50 %

20-30 %


(3) q_hat = 14 GeV2/fm



(4) dNg / dy = 1000

non-photonic electron v2 is similar with other hadronsnon-photonic electron v2 is similar with other hadronsat low pat low pTT but smaller at higher p but smaller at higher pTT region 4~5GeV/c region 4~5GeV/c

photonic electron v2 originated from photonic electron v2 originated from 00

is above is above 00 v2 at low pT and similar to v2 at low pT and similar to 00 v2 at high pT and v2 at high pT and subtracted already.subtracted already.

Non-photonic electron is less suppressed compared with 0, but it is still a significant suppression RAA~ 0.3 at higher pT region 4~5GeV/c

Non-photonic electron (charm origin) RAA compared with 0 RAA

Important note : RAA is much closer to unity at lower pT compared with 0 or other hadrons


B. Zhang et al.nucl-th/0502056

significant suppression at higher pT, almost same as 0 suppression above 5GeV/c

b contributionless suppressionless interaction

b contributionless flowless thermalized

Non-photonic electron : charm (+beauty) RAA and v2

some difference between experiments at higher pT, which needs to be solved. D-meson flows (+ve v2), should determine charm v2


rather good description above 1GeV/c in quark pT

remaining mass dependence at lower pT region

QM05 PHENIX QM05 STAR

Number of quark scaling of v2

v2 is already formed during quark phase before hadronizationadditional hadronic flow might be there after hadronization

overview of heavy flavor v 2

Documents

nonphotonic electron

simulatione v2

converterinclusive electron

p0 v2 measurement

measurement smaller

centyieldper esumi

zhangshinichi esumi

issahshinichi esumi