# Presentation: 904213

## 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 

- RHIC @ Brookhaven National Laboratory

**h**

**Long Island**

**R**elativistic
**H**eavy
**I**on
**C**ollider

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

**STAR**

**PHENIX**

**PHOBOS**

**BRAHMS**

## 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

**Notes:**
To do the measurements, we need:
collidor
detector
and study appropriate physics process

here I will focus on two areas:
heavy quarks and W/Z productions

## PHENIX Detectors

- Central Arms
- EMCal
- Tracking
- PID
- photons,electrons
- hadrons 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

## Slide 7

## Slide 8

## Artist’s View of PHENIXa 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/RIKEN
- Joel 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**

## Slide 21

## 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

- 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

*Experimentally*

- - Naïve expectation   = 1

- RHIC-Spin Physics
- New 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?

- Heavy Quark productions

- W productions

## 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.

*Experimentally(indirect)*

- HERMES’99

- Gluons may play a significant role !

## pQCD and Factorization Model

- Measures of Asymmetry
- Polarized PDF

## Polarized Interactions

- Measures of Asymmetry

## Heavy Quark Production and G 

- Gluon-Gluon scattering
- dominant process at 200 GeV

## Heavy Quarks in PHENIX

- Open Charm/Bottom
- high Pt single leptons
- work in progress
- lepton charge correlation
- displaced vtx (upgrade)

- Jet

- lepton

- Pt_jet

- VTX

- IP

- b

- _
- b

***SVX Upgrade***

- J. Moss, M.Brooks, `97

## Heavy Quark Production and G 

- Single Lepton Asymmetry

- 32pb-1

## Heavy Quarks in PHENIX

- Quarkonia
- J/(1S), (2S)
- (1S), (2S)
- x1,x2
- di-lepton

## Measurement of J/ Polarization   	- study QCD spin & fragmentation dynamics   	- a new QGP probe? 

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

- CDF

- SVX Upgrade is important !

**Notes:**
Measurement of J/psi polarization will be a crucial test for the color octet model since it predicts large transverse polarization at high pT. 
Experimentally, we measure decay angle distribution at the CM system of the J/psi. This is an expected distribution when we assume unpolarized J/psi. 
Sensitivity of alpha is 0.02 for pT is over 2GeV/c J/psi, and 0.1 for pT is over 5GeV/c J/psi.

## Polarized PDF

- u
- d
- s

- A Model

## Slide 34

## Flavor Asymmetry & Sea Quark Polarization

- Sea quarks  are
- NOT flavor
- symmetric

- E866

- Pion cloud modle
- Chiral model

## Quarks and Anti-Quarks Polarization

- Limits of DIS
-  Asymmetry in W productions
- (V-A) coupling in W productions
- Quark flavor selection

## Quark and Anti-Quark Polarization 

## Quarks and Anti-Quarks Polarization

## Searching for New Physics

- 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

## Searching for New Physics

- Drell-Yan process
- Z’, SUSY etc
- Better sensitivity

- excess

## 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**** *

## Backup slides

## 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%

## Slide 45

## 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 PHENIXin the early days...

- First PHENIX Logo

## Slide 52

## Slide 53

## Slide 54

## Slide 55

## What is MVD?

- Mike’s talk

## Heavy Quark Production and G 

- Di-lepton Asymmetry
- A_LL experimental sensitivity
- first goal:
-  measure G large

***P*→ ***A**LL**/A**LL**~**20%*

- 320pb-1

## Comparison with Others

- RHIC Spin
- 10 weeks vs HERMES
- published results
- x10 statistics
*u* quark: HERMES
*d* quark : RHIC Spin
- sea quark:RHIC Spin