P-25 RHIC-SPIN research program

• RHIC Physics – Quark-Gluon Plasma (HI), Mike’s talk– Nucleon Spin Structure (RHIC-SPIN)

• History of PHENIX-SPIN(20%)• RHIC-SPIN physics and LANL (50%)

– shift focus from construction to physics analysis– Physics Interest

• Current activity (30%)– Hardware and Software– Physics Analyses

RHIC @ Brookhaven National Laboratory

h

Long Island

Long Island

Relativistic

Heavy

Ion

Collider

• 2 concentric rings of superconducting magnets• 3.8 km circumference• counter-rotating beams of ions from p to Au

STAR

PHENIX

PHOBOSBRAHMS

The Experiment

PHENIX=Pioneering High Energy Nuclear Interaction eXperiment • Polarized Protons at RHIC

– E_cm=50 - 500 GeV

– P=70%

– L=2x10^32 cm^-2sec^-1

• Particle Detectors– PHENIX etc

• Physics Studies– Nucleon Spin Structures

– P,CP Violations

– New Physics

PHENIX Detectors• Central Arms

– EMCal– Tracking– PIDphotons,electronshadrons PID

• Muon Arms– tracking + ID

• LANL Group– Muon Arms– MVD– SVX upgrade

PHENIX in Today

In the early days …• Not a story of “in the good old days ….”

– 9 or so proposals altogether in 1991, among them TALES, SPARC, OASIS and DIMUON were forced to merge.

– STAR was pre-selected!

• PHENIX vs STAR

– Combination of several proposals

– Funding problems, de-scoped, only one muon arm

– A hard time to bring all subsystem together

– Could fall into crapes

Artist’s View of PHENIXa little bit of history about Muon Arms in PHENIX

(thanks Hubert)

LANL made the difference• Brought in Japanese/RIKEN $$ to RHIC/PHENIX-

Spin - Joel Moss, Masayasu Ishihara(RIKEN) et al• PHENIX Spin program

STAR WAR?

BNL-RIKEN Agreement

• Signing of the BNL-RIKEN Agreement on Spin Physics, September 25, 1995 at BNL– With $20M From Japanese Lab, RHIC Ventures

Into Spin Physics• Half of the money that RIKEN

brings to the collaboration will be used to build and install the Siberian snakes, spin rotators and other hardware needed to collide spin-polarized protons in RHIC.

• The other $10 million will buy an additional detector system for PHENIX, one of the two large detectors now under construction for RHIC, which will allow this experiment to do spin physics.

Origins of the Los Alamos Involvement in the PHENIX detector Program (from JJM, DOE/NP Review, 96)

• Circa 1990: two groups with interest in RHIC – Fermilab E722/E789 and CERN NA44– [SPIN Puzzle ~1988, EMC]

• Spring 1990: Decision made that P-Division would enter the RHIC program in a major way and focus its efforts on one experiment. Major players - Barbra Jacak, Mike Leitch, Pat McGaughey, Joel Moss. High Q^2 physics

• 1991-1993: PHENIX collaboration evolves. – Keep P-Division Physics agenda part of the detector: major roles played by Barbra Jacak and

Pat McGaughey. – Save muon arms from total oblivision: major role played by Pat McGaughey (acting DC head)– MVD becomes LANL responsibility (Barbra Jacak, DC head)

• 1993-95: Los Alamos collaboration on spin physics at RHIC. Secured instrumentation for the north muon arm and added new (south) muon system. Major role played by Wayne Kinnison, John McClelland and Joel Moss.

NOTE: Without Los Alamos efforts there would be NO muon subsystem in PHENIX and probably no phenix-spin program

PHENIX-Spin collaboration

Spokesmen: Ken Imai, Kyoto/RIKENJoel Moss, LANL

Physics @LANL• Nucleon structure

– Understanding the structure of nucleon in terms of quark and gluon constituents of QCD is one the outstanding fundamental questions in physics.

• LANL experience, expertise & interests – E772/789/886: dimuons– sea quark flavor asymmetry– Gluon shadowing– Spin structure function– QCD dynamics– New physics– DY,J/Psi, heavy quarks etc

LANL Effort in PHENIX

• Contributed 3 major subsystems– Muon arms: simply the largest – MVD: the smallest in size but the largest in channel

numbers

• Muon software– On-line– Off-line

• First Year Muon Physics– J/Psi from p+p and Au+Au (QM2002)– Heavy quark physics w/ single and dimuons, in progress

• MVD and SVX upgrade for PHENIX – Mike and Gerd’s talks

PHENIX Muon Arms

• Muon Arms – Tracking+MuID– 1.2 < || < 2.4 =2– p 2GeV/c

• Drell-Yan• Heavy Quarks• W,Z• Critical for Spin

Physics

Muon Arms• How Muon Chamber works

Muon Arms• Mass Resolutions for VM:

Resolve (1.02 GeV) from (0.77 GeV) + (0.78 GeV) and optimize signal to background.

Resolve J/(3.097 GeV) from ' (3.686 GeV) and optimize signal to background.

Resolve (1S) (9.46 GeV) from (2S+3S) (10.02 + 10.36 GeV) over all rapidity (including central rapidity).

• Physics Simulations:

mass resolution 80 MeV/c2

J/ mass resolution 110 MeV/c2

mass resolution 200 MeV/c2

W/Z decays dp/p~15%

– Δp/p~3% (@3~10GeV/c)

Critical for Spin Physics

Muon Factory

• Clean Room • Test Area

PHENIX South Muon-Spectrometer

•Three very large detector stations in 8 octants with 20,000 anode wires and 22,000 cathode strips

•low noise electronics

•8 meters high and weighs around 300 tons•over 10 miles of cables

J/Psi from the First Year

• Proton Structure and Spin Puzzle– Proton Spin Decomposition

– Origin of Proton Spin: gluon, sea quarks ?

• A new tool to study QCD

• Test of Fundamental Symmetries– Parity & CP Violations

– New Physics

02.010.0

04.031.0

s

sdu

LG 2

1

2

1

Experimentally

- Naïve expectation = 1

RHIC-Spin PhysicsRHIC-Spin PhysicsNew Frontier of Nucleon Structure ResearchNew Frontier of Nucleon Structure Research

RHIC-Spin PhysicsRHIC-Spin PhysicsNew Frontier of Nucleon Structure ResearchNew Frontier of Nucleon Structure Research

- RHIC: large Q^2

- JLab: small Q^2

Experimental Approach

• Proton spin decomposition

• Burning questions – Gluon Polarization? – Sea-quark polarization? – Flavor dependence?

LG 2

1

2

1

Heavy Quark productions

W productions

3.0

Gluon Polarization – the 1st thing we want to look at

• Proton Spin Puzzle and G

• Asymptotic limit

• Experimental approach:– heavy quarks (LANL)

– jet+direct photon

– high Pt hadrons, QCD evolution, etc.

Gq

qG

JJ

LG

2

1

2

1

17.0;03.018.041.0)(

)(

Gx

xG

xG

Experimentally(indirect)

HERMES’99

2Q

fGG

f

fqq

nLGQJ

n

nLQJ

316

16

2

1)(

316

3

2

1

2

1)(

2

2

Gluons may play a significant role !

pQCD and Factorization Model• Measures of Asymmetry

• Polarized PDF

dt

dQxFQxF

dp

dE

cdab

bb

Baa

A

),(),( 22

3

3

1

0)(

)()()(

dxxFF

xFxFxF

LG 2

1

2

1

Polarized Interactions

)()()()(

)}()({)}()({)}()({)}()({

L

LL

A

A

• Measures of Asymmetry

)()()()(

)}()({)}()({)}()({)}()({

T

TT

A

A

Heavy Quark Production and G

• Gluon-Gluon scattering– dominant process at 200 GeV

%95: ccggcc

)()(

)(

)(

)(

2

2

1

1 QQggaxG

xG

xG

xGA LLLL

Heavy Quarks in PHENIX• Open Charm/Bottom

– high Pt single leptons– work in progress

• lepton charge correlation• displaced vtx (upgrade)

b cW-

-

s

W+

+

Jet

leptonPt_jet

VTX

IP

b_b

SVX Upgrade

J. Moss, M.Brooks, `97

Heavy Quark Production and G • Single Lepton Asymmetry

a

AQQgg

LL

XQQpp

LL

xG

xG

xG

xG

xx

)(

)(

)(

)(

),(

2

2

1

1

21

1.12

ˆ

M

s

1.5

2

5

32pb-1

Heavy Quarks in PHENIX

• Quarkonia– J/(1S), (2S) (1S), (2S)

– x1,x2

• di-lepton%6)/( JBR

Measurement of J/ Polarization - study QCD spin & fragmentation dynamics

- a new QGP probe?

*cos1*cos

2

d

d

α= +1: transversely polarizedα= -1: longitudinally polarizedα= 0: no polarization

+J/

*-

CDF

SVX Upgrade is important !

Polarized PDF)(/)( xuxu

)(/)( xdxd

uds

q

vu g

vd

A Model

Flavor Asymmetry & Sea Quark Polarization

Sea quarks areNOT flavor symmetric

E866

)()(

)()(?

xdxu

xdxu

Pion cloud modleChiral model

Quarks and Anti-Quarks Polarization

• Limits of DIS

• Asymmetry in W productions– (V-A) coupling in W productions

– Quark flavor selection

)()()()(

)()()()(

baba

babaWL xuxdxdxu

xuxdxdxuA

),(9

1

),(9

1),(

9

4

2

1),(

2

22

21

Qxss

QxddQxuuQxg p

Quark and Anti-Quark Polarization

vW

1*

2*

1*

)cos1(4

])cos1()cos1[(4

xs

xxs

E

sMxx

d

d

W

W

/

)cos1(cos

21

2**

W

0Z

Quarks and Anti-Quarks Polarization

ba

ba

baba

babaWL

xxifxd

xd

xxifxu

xu

xuxdxdxu

xuxdxdxuA

)(

)(

)(

)(

)()()()(

)()()()(

ba

ba

baba

babaWL

xxifxu

xu

xxifxd

xd

xdxuxuxd

xdxuxuxdA

)(

)(

)(

)(

)()()()(

)()()()(

Searching for New Physics

_d

u

+

2

2

2 WM

gG

)1()1(8 552

2

gLqqqq

Why Parity Violation?- unexplored at high energy- Z-pole @SLAC, CERN

Rb, Ab etc- sensitive to new physics

many models of NEW PHYSICS predict PV,CPV

AL in contact interaction- Jet + X- high Pt muon + X- Drell-Yan

Low Energy:

Searching for New Physics Discovery opportunity in Drell-Yan channel

• Required Luminosity for Discovery on Drell-Yan

• Required Luminosity for Discovery on Drell-Yan

Searching for New Physics• Drell-Yan process

– Z’, SUSY etc– Better sensitivity

excessexcess

dmdyd

dmdyd

dmdyd

dmdyd

Ldmdyd Avs

)(2)(2

)(2)(22

Summary• Unique Opportunity

• Discovery Potentials– study PV, CPV etc.

– New Physics @RHIC• P-25/T8 joint effort

• LANL advantage – Experience & expertise

– P/T collaboration

• Shift to PHYSICS Study

...,,);(),(

)(

sdufxqxq

xG

ff

q

vuG

vd

Backup slides

BRAHMS & PP2PP (p)

STAR (p)

PHENIX (p)

AGS

LINACB OOST ER

Pol. Proton Source500 A, 300 s

GeVs

cmsL

50050

onPolarizati%70

102 2132max

Spin Rotators

Partial Siberian Snake

Siberian Snakes

200 MeV Pola rimeter AGS Inte rnal PolarimeterRf Dipoles

RHIC pC Pola rimeters

Absolute Polarimete r (H jet)

2 1011 Pol. Protons / Bunch = 20 mm mrad

Run 2 Spin Summary• Luminosity

– 0.15pb^-1

• Polarization– 25%

• L_eff = p^2*L

= 6nb^-1

• Physics– Transverse Spin A_N

• pi(0,+,-), photon• forward muons• forward particles

– Single Spin Asymmetry 70% 25%

25%

Asymmetries from Y1

LANL activities

• Muon arm construction– South arm: 2001– North arm: 2002– Show some pictures

• Mechanical – Dave Lee, Walt, Melynda, Rusty• Electroincs – Dick, Melynda, Mike, Pat, Ming• Software – Melynda, Pat, Mike, Ming

– First year physics• J/Psi from pp and AuAu • Single and dimuons from heavy quark decay• Forward polarimeter

• MVD – Mike’s talk– Provides vtx for muon reconstruction

PHENIX Today

History & Current activities

• Los Alamos and PHENIX/RHIC-SPIN• Muon arms & MVD• SVX upgrade• HI physics – Mike’s talk• Spin - focus

– J/Psi, DY, heavy quark and W/Z physics with muons– Gluon polarization– Sea quark polarization (E866 – unpolarized sea quark)

• This is the time to shift from construction to physics study; • our 10 years construction effort should be paid off with

strong physics results

History of PHENIX and LANL involvement

• Why do I want to talk about this?– Our commitment made 10 years ago

– Major role played by LANL in construction and physics ideas

• LANL played a major role in bringing PHENIX and SPIN program into life– Key players : Joel, Pat, John, Barbra, Mike, Wayne, etc.

• Bottom line - we started the program and we want to finish it with good physics results

Artist’s View of PHENIXin the early days...

What is MVD?• Multiplicity Detector at PHENIX Interaction Vertex

•Acceptance: = 5 and full azimuth

Mike’s talk

Heavy Quark Production and G • Di-lepton Asymmetry

– A_LL experimental sensitivity

– first goal:

measure G large

)()(

)(

)(

)(

2

2

1

1 QQggaxG

xG

xG

xGA LLLL

1.12

ˆ

M

s

1.5

2

5

LNLN

LNLN

PPA

BBLL

21

1exp

%11

.)( 2 totB

LLNP

statA

P→ ALL/ALL~20%

320pb-1

Comparison with Others

• RHIC Spin 10 weeks vs HERMESpublished results x10 statistics

– u quark: HERMES– d quark : RHIC Spin– sea quark:RHIC Spin