justin frantz ohio u niversity for the pheni x collaboration

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STEPS FROM QUALITATIVE TO QUANTITATIVE: PROMPT

PHOTON PRODUCTION AND PHOTON-JET -HADRON CORRELATIONS IN PHENIX

Justin FrantzOhio University

For the PHENIX Collaboration

gg

g

8/14/2012

Justin Frantz - PHENIX2

Trigger g E calibrates the partner jet to leading order Purely jet/hadronic observables clouded triggers

themselves are modified Geometric surface bias of the single jet, di-jet ? Direct g production unmodified by medium: no

surface bias for g vertices Plus dominant partonic type becomes purely q-jets

compared mainly g-jet/mix in jet-jet (q vs g Eloss differs)

Compton Diagram

A “golden” HI jet Eloss channel: g-Jet

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Step 1: strengthen baseline from elementary p+p collisions

How to make direct photon results more quantitative

g

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Strong New p+p measurement! New high statistics

dataset pT range x2 Precision Improved > x 2

More precise isolated fraction

~90% Iso in R = 0.5 cone

!Submitted PRD arXiv:1205.5533

PHENIX Final

Isolated Ratio

8/14/2012

http://arxiv.org/abs/1205.5533


How to make direct photon results more quantitative

Step 2: Master your systematics and finalize 2004 golden dataset analysis

gg

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Moving Forward…Finalized Au+Au

More precise spectra measurement published!

2004 Dataset systematics (e.g. p0 merging) studied in great detail

Submitted PRL arXiv:1205.5759

8/14/2012



Final Au+Au RAA Lack of suppression re-confirmed Substantial high pT suppression in prompt photon

no longer looking viable (esp. combining with other data)

Should we be using iso component as p+p reference? More Jet-Medium-like enhancement?


Cu+Cu 200?

See poster 24B. Sahlmueller

8/14/2012



“New” d+Au Direct g Result: High pT Direct photons: d+Au, A+A initial state effect

tester! At low pT using PHENIX-invented virtual g di-electron

method (yellow error bars) Up to moderate pT—not just soft! Confirmation of method

High pT newly finalized 2003 Calorimeter data 2003 d+Au RdA made more precise by new p+p Consistent dAu RdA vs AuAu RAA

8/14/2012


From control to hot medium modification observable:Photon-Hadron results

Use the “unmodified” photon as calibration for the modified awayside jet

8/14/2012

Justin Frantz - PHENIX

2-particle Statistical Method

Subtraction w/ flow modulation included Abs. Norm subtraction 10

Bkg(Flow)Norm

g-h: subtraction of 2-p Df12 measurements Rg directly from new single direct g analysis

Bkgdecay(Flow)

Ydirect ∝ Cdecay - Cincl - Bkgincl (Flow)- [ ]

+v3 + v4…

C(Df)

dN/dDf

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Yinclusive = Incl. -h Ydecay~ 0 -h


Pre-QM12: 2007 Result

Df-Integrated yield plotted vs. zT

zT = pTh/pTg

or =x ln(1/zT) Frag Fn ! D(zT) or D( )x Suppression signal: clear at low z (high x) Hint at rise in shape/

enhancement (Qualitative!)

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g-h Fragmentation Function

8/14/2012


How to make this result more quantitive

Add 2010 dataset Combined statistics of 2007 + 2010 datasets

Combine centrality 0-20% + 20-40%

g-h

8/14/2012


Pied de Resistance! Suppression at high z, low x -- universal 2-p phenomenon

LHC non-effect at z = 1 is only within ID’d jets 2-p method IAA includes/accounts for “lost” jets and particles

Enhancement signal at low z, high x now statistically significant! Theory qualitatively similar : recovery of lost/radiated energy

8/14/2012


Where is this enhancement?

Low z Low associated hadron pT

Enhancement increasing at larger angles from away jet

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Integrations in different Df rangesQuantitative-ness

Integrating in different ranges shows quantitative evolution with awayside angle

Qualitatively consistent: Rise from low xi to high xi present in all integration ranges

Less in the “head” region! Broadening of the awayside fragmentation!

Posters:N. Riveli21B. Xia – 23

8/14/2012


Just Effect of vn ? Test: Conservatively large

guestimate for high pT v3,4 (RHIC measure unavailable)

Visible change for gdec-h (h-h) and gincl-h but broadening still present

Mostly cancels in g subtraction Assuming direct g vn = 0.5 vn

of p0 chosen as max vn RHIC Integrated yields difference

generally much less (v3 effect in Df of 2pi/3 ~ 0!)

gincl-h gdecay-h5-7 x 1-2v2 onlysubtracted

5-7 x 1-2v2+v3+v4subtracted

All of broadening due to v3? No!

v1 effect should be small too. e.g. see T. Todoraki parallel talk 6D

8/14/2012


Conclusions Au+Au single Direct g non-suppression re-confirmed w/

more precise finalized p+p and Au+Au data Isolated reference for p+p: enhancement in the Jet-Medium

area? New d+ Au, A+A single direct g interesting to compare

CNM effects seen in jets Fragmentation Function modification seen with

statistical significance! Enhancement at low z/high x: recovery of lost energy? Increasing at wide angles from away jet direction

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Backups

8/14/2012


"Hate and the killer were not successful. He wanted to divide and we have come together."

PRABHJOT SINGH, co-founder of the Sikh Coalition, at a memorial service for six worshipers slain at a Sikh temple in Oak Creek, Wis.

-NYT

8/14/2012


Jet pt, angular ranges, and centrality? With more statistics try to study various

differential dependences…TRIGGER PHOTON (~JET PT?) DEPENDENCE

CENTRALITY DEPENDENCE

-Consistent qualitative trends-Hint of enhancement at diff xi (pTa, pTt dep)?

-Low z/high z suppression dependence consistent w/ expectations?-Hint of enhancement at diff xi (pta,ptt dep?-Enhancement persists

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Justin Frantz - PHENIX218/14/2012


Initial state effect? Like jets? Looking for initial state effects in g is especially

interesting given jet sector results 20032008 dataset will allow for centrality dependence

for gdir RdAu. Different than surprising jet dependence?

8/14/2012


Direct g Motivation II

A+A Initial state effect tester! In A+A this is the only modification possible (for

Compton/Iso component)!

Big step: understand initial state/ CNM effects for jets

To understand CNM effects in A+A start with to p+A, d+A

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Jet Fn’s

8/14/2012


Jia: wwnd12: v1 slide: Fit result vs pT and centrality

v1Fit(pT) peaks around 4-5 GeV,

peak-value increases with centrality by about 20%. Less viscosity damping,

reflecting the increase in ε1?25

Glauber

8/14/2012


sPHENIX (?) Rates for Direct g are 1/1000 of Jets But still sufficient statistics at

RHIC for good overlap of jet, leading particle results Because of spectral shapes RHIC has better S/B for Direct Gamma

(/Pi0) than LHC: better high pT stats than Pi0 !

…from sPHENIX Proposal 2012:

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Isolation cut

Isolation cuts in p+p New cone size 0.3 0.5

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Good Agreement PHENIX/STAR

Strong Suppression Signal both collaborations

At about ~0.3

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zp

pTTh

Ttrig

-h

IAA

Dd+Au

Baseline

STAR Preliminary STAR Preliminary

PHENIX split into smaller trigger bins

8/14/2012


Compare to CMS Frag Function REsult Comparing to the CMS data might be telling us it’s a Hard/Soft

Division, not scaling w/ z

Also apparent in STAR jet-h …

CMS-PAS-HIN-11-004 Marguerite Tonjes Monday

8/14/2012


New d+Au Direct Photon

At low pT using virtual di-electron method Up to moderate pt

—not just soft! High pT newly

finalized 2003 Calorimeter data Newly relevant due

to much better p+p data


8/14/2012



Compare to Reco’d Jet-h RHIC TO RHIC

Interesting to compare results to jet reco

Qualitatively similar Same conclusions

Alice OhlsenSTAR Prelim

low zlow z

Hmmm…

low z

8/14/2012


Don’t forget Df Shapes Themselves

Some of Reco Jet IAA enhancement is coming in ~same Df region as “ridge”/”shoulder”/ (probably) ”v3” ? Needs further investigation

Direct -g h too? I know for both analyses work is well underway…

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v3?

8/14/2012

justin frantz ohio u niversity for the pheni x collaboration

Documents

g vertices

p p reference

golden dataset analysis

jetjet q vs g eloss

direct g production

phenix collaboration

phenixinvented virtual

elementary p p collisionshow