04/19/23 1

E.Kistenev, BNL

PHENIX in the next decade

Erice, September 17, 2012

Slides contributed by J.Nagle, W.Zajc, D.Morrison, D.Karzeev, V.Pantuev

2002: discovery of high pT suppression at RHIC

D.Karzeev, 2004RHIC II and dedicated program at RHICII are necessary to extend our

understanding of collective QCD phenomena discovered at RHIC

Suppression of hadrons with large transverse momentum in central Au+Au collisions at √sNN = 130 GeV, PHENIX Collaboration (K. Adcox et al.), Phys.Rev.Lett.88:022301,2002

664 citations

Since 2002 the goal was to confirm that the

observed high pT suppression is indeed due to the parton energy loss in the media:

- Search for fluctuations –> transport coefficients;- Energy scan -> search for critical point;- Studies of the suppression dependence on the quark

mass;- Studies of the suppression dependence on collision

energy (RHIC vs LHC);

CMS, PbPb, Isolated photons, 2.76 TeV

Systematic investigation of variations with s

4 2.76 TeV at LHC very similar to 200 GeV at RHIC!

Challenge: Solving a multi-scale, highly dynamic Challenge: Solving a multi-scale, highly dynamic transport problem in an intrinsically quantum transport problem in an intrinsically quantum systemsystem..

Rewards:Rewards: Possible resolution of quasiparticles Measurement of shear viscosity to entropy ratio /s Measurement of transport coefficients

in a fundamental gauge theory

The Intellectual Challenges and Rewards

W.Zajk, Tribble com. talk

L

Ee

L

pq LL

T ˆˆ

2

6

Mapping Out Media Coupling with Jet Probes

s

Tq

/

25.1ˆ

3

Key is independently measuring both sides of this equation!

Scenario #1 (x10)

reveals peak in q !

^

QCD Weak Case

RHIC Perfect Fluid

A. Majumder, B. Muller, X.N. Wang, PRL (2007).“Small Shear Viscosity Implies Strong Jet Quenching”

Liao and Shuryak, PRL (2009)“Jet Quenching is a few times stronger near Tc relative to the QGP at T > Tc.”

In a weakly coupled turbulent plasma

Range of estimates: (Compilation

by A. Tang,R.J. Lacey)

Estimated “error band”

Indirect “bounding” /s at RHIC

PHENIX, PRL (2010)“Large v2 is striking in that it exceeds expectations of pQCD models even at 10 GeV/c”J.Liao arXiv:1209.1052v1 [nucl-th] 5 Sep 2012“AdS/CFT-motivated model with cubic path-length which enhances the late time quenching that mimics the near-Tc enhancement describes v2 at high pt for RHIC”

Jet or photon

Jet/photon tagging for q measurements

9

Fractional momentum lossMeasure fractional momentum loss (dpT/pT) instead of RAA

Different dpT/pT for same RAA

pT

LHC

RHIC

pT/p

T

RHIC and LHC give a key lever arm in temperature

RA

A

arXiv:1208.2254

Horowitz and Gyulassy, NPA (2011)“The surprisingly transparent sQGP at the LHC [compared to RHIC]”

Analogy: e - energy loss in electrical field

Can RHIC precisely measure key observables

Rates are huge. They will allow differential measurements with

varying collision geometry (v2, v3, A+B, U+U, …) & precision control

measurements (d+Au and p+p) !!

Au+Au(central 20%)

p+p d+Au

>20GeV107 jets

104 photons106 jets

103 photons107 jets

104 photons

>30GeV106 jets

103 photons105 jets

102 photons106 jets

103 photons

>40GeV 105 jets 104 jets 105 jets

>50GeV 104 jets 103 jets 104 jets

Based on full stochastic cooling, no additional accelerator upgrades

Further Leveling the playing field with LHC

Use advantages of RHIC (machine is dedicated to HI physics);

Vary the species (shape, isotopic content);

Study threshold behavior varying collision energy;

Do better measurementsLHC comparable or increased coverage;comparable or better resolution;better hermeticity, uniformity

ambitious upgrade to study the sQGP with a new compact, hermetic, large acceptance and high rate

calorimetry based detector

High statistics Upsilons , large Dijet and -jet rates with full calorimetry, photon/charm/beauty tagging of jets with PreShower/VTX,

low-x jet, , quarkonia, transverse spin probes, staged into ePHENIX detector.

sPHENIX Decadal Plan

Specs for NEW sPHENIX Central Detector

1304/19/23

sPHENIX MIE Project (major item of equipment)

1404/19/23

Magnet• Solenoid 2 Tesla, Rinner = 70 cm

Accordion Tungsten-Fiber EMCal

Fe-Scintillator HCal• Also acts as flux return for magnetic field

1504/19/23

18GeV

19GeV15GeV

6GeV

16GeV

truth jets reconstructed jets

25-30 GeV reconstructed Jets are dominated by real jets (known from HIJING truth)

Full HIJING Event Analysis

Very good jet finding efficiency even in the most central Au+Au

events for ET > 20 GeV

Jet Transverse Energy (GeV)

sPHENIX Electromagnetic Calorimeter

1604/19/23

sPHENIX Hadron Calorimeter

Response

~ 75%/√E

Tilt tuneup (mip’s)

First look on HC performance

18

Summary

Heavy Ion Collisions produced major discoveries in “Physics in Collisions” in the last 10 years, jet quenching and unexpectedly strong elliptic flow are two examples.

In the era of LHC RHIC still offers unique opportunities for detailed studies of matter phase transition on a phase boundary close to critical temperature. We need the lever arm of RHIC and LHC together to find a fundamental explanation for how the perfect fluid emerges at strong coupling near Tc from an asymptotically free theory of quarks and gluons.

Calorimetry based upgrade to PHENIX will create a tool to explore this opportunity with jets and direct photons being event observables and event tags of choice.