# Presentation: 535365

##                    Status and Recent Results

**Matthias Grosse Perdekamp, UIUC and RBRC**

- PHENIX status and run 2003 performance
- High sensitivity to rare processes
-                    J/  and high pT hadrons  in
-                    Au-Au, d-Au and p-p collisions
- Brief review of run 2002 results
- Hadron production at high transverse momenta
-                  charged hadrons  and 0  in Au-Au and p-p
-                  First look at PHENIX d-Au data

##  12 Countries;  57 Institutions;  460 Participants

**             ****Brookhaven National Laboratory, Upton, NY **
**             ****University of California - Riverside, Riverside, CA**
**             ****University of Colorado, Boulder, CO**
**             ****Columbia University, Nevis Laboratories, Irvington, NY**
**             ****Florida State University, Tallahassee, FL**
**             ****Georgia State University, Atlanta, GA**
**             ****University of Illinois Urbana Champaign,  IL**
**             ****Iowa State University and Ames Laboratory, Ames, IA**
**             ****Los Alamos National Laboratory, Los Alamos, NM**
**             ****Lawrence Livermore National Laboratory, Livermore, CA**
**             ****University of New Mexico, Albuquerque, NM **
**             ****New Mexico State University, Las Cruces, NM**
**             ****Dept. of Chemistry, Stony Brook Univ., Stony Brook, NY**
**             ****Dept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY  **
**             ****Oak Ridge National Laboratory, Oak Ridge, TN**
**             ****University of Tennessee, Knoxville, TN  **
**             ****Vanderbilt University, Nashville, TN****	****                                                                                                **

**Brazil        University of São Paulo, São Paulo**
**China        Academia Sinica, Taipei, Taiwan**
**                  ****China Institute of Atomic Energy, Beijing**
**                  ****Peking University, Beijing**
**France      LPC, University de Clermont-Ferrand, Clermont-Ferrand**
**                  ****Dapnia, CEA Saclay, Gif-sur-Yvette**
**                  ****IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, Orsay          **
**                  ****LLR, Ecòle Polytechnique, CNRS-IN2P3, Palaiseau**
**                  ****SUBATECH, Ecòle des Mines at Nantes, Nantes**
**Germany  University of M****ü****nster, M****ü****nster**
**Hungary  Central Research Institute for Physics (KFKI), Budapest**
**                 ****Debrecen University, Debrecen**
**                 ****Eötvös Loránd University (ELTE), Budapest **
**India          Banaras Hindu University, Banaras**
**                  ****Bhabha Atomic Research Centre, Bombay**
**Israel         Weizmann Institute, Rehovot**
**Japan       Center for Nuclear Study, University of Tokyo, Tokyo**
**                  ****Hiroshima University, Higashi-Hiroshima **
**                  ****KEK, Institute for High Energy Physics, Tsukuba **
**                  ****Kyoto University, Kyoto**
**                  ****Nagasaki Institute of Applied Science, Nagasaki**
**                  ****RIKEN, Institute for Physical and Chemical Research, Wako**
**                                               ****RIKEN-BNL Research Center, Upton, NY              **
**                  ****University of Tokyo, Bunkyo-ku, Tokyo**
**                  ****Tokyo Institute of Technology, Tokyo**
**                  ****University of Tsukuba, Tsukuba **
**                  ****Waseda University, Tokyo                    **
**S. Korea   Cyclotron Application Laboratory, KAERI, Seoul**
**                  ****Kangnung National University, Kangnung**
**                  ****Korea University, Seoul **
**                  ****Myong Ji University, Yongin City **
**                  ****System Electronics Laboratory, Seoul Nat. University, Seoul**
**                  ****Yonsei University, Seoul**
**Russia       Institute of High Energy Physics, Protovino **
**                   ****Joint Institute for Nuclear Research, Dubna **
**                   ****Kurchatov Institute, Moscow**
**                   ****PNPI, St. Petersburg Nuclear Physics Institute, St. Petersburg**
**                   ****St. Petersburg State Technical University, St. Petersburg**
**Sweden     Lund University, Lund**

*** ******12 Countries;  57 Institutions;  460 Participants***

##       PHENIX: Run History

-       PHENIX: Run History

**2000**

**2001/2002**

**2002/2003**

##       PHENIX Status in 2003: Design Configuration!

-       PHENIX Status in 2003: Design Configuration!

**Central Arm Tracking**
-       Drift Chamber
-       Pad Chambers
-       Time Expansion Chamber
**Muon Arm Tracking**
-       Muon Tracker:  **North Muon Tracker**
**Calorimetry**
-       PbGl
-       PbSc
**Particle Id**
-       Muon Identifier: **North Muon Identifier**
-       RICH
-       TOF
-       TEC
**Global Detectors**
-       BBC
-       ZDC/SMD  **Local Polarimeter**
**      ****Forward Hadron Calorimeters**
-       NTC
-       MVD
**Online Calibration and Production**

##  The PHENIX Detector:  Central Arms                          

-  The PHENIX Detector:  Central Arms

##       Two Collisions as seen by the PHENIX Central Arms

-       Two Collisions as seen by the PHENIX Central Arms

- 2001/2002 Au-Au

- 2001/2002 d-Au

## DAQ and Trigger System: Rare Event Capability

-      Front End
-      Electronics
- (25000 Channels)

- Buffers: 4s deep

**... ****14 Subsystems**
- (350000 Channels read
- every 106 ns leading to
- a data volume: 3.5TB/s)

- EMC

-     Subsystem
-       Trigger
-      Processor

**... ****6 Subsystems**
- (NTC, BBC, ZDC,
-   EMC, RICH, muID)

-         Level 1
-        Trigger
-       Processor

- Trigger   Request
- not to exceed 1kHz

-         Event
-     Builder SEB
-      (37 CPUs)

-  120MB/s

-          ATP
-      (23 CPUs)

-           120MB/s
-        Data Storage
-             40 TB

- Primitives for higher
- level trigger decision

- Write   events
-      at    1.0kHz

-         DCMs

- Trigger configuration in d-Au
-    o Raw rate < 50 kHz
-    o First level trigger:
-          3 minimum bias
-             1single electron (J/)
-             1electron pair ()
-             4 photon (0.8, 2.1, 2.8, 3.5 GeV)
-             2 muon
-             2 di-muon (J/)
-    o Level 2: off
-    o Extend to 300kHz in p-p

**DAQ**

**Filter**** ****(shift crew)**

**Pulser 0**
**Pulser 1**
**Pulser 2**
**Electron **
**Photon: 2.1 GeV**
**Di-muons**

**Bufferbox **
**a/b**

- Calibration: BBC, EMC, FCAL, ...
- Evaluation J/(->ee,), 0

- Online Calibration, Evaluation and Production

**PHENIX**
** ****Online**

-     PHENIX
- online pc-farm

## Run 2003 d-Au         200 GeV

- ~ 232 J/’s
- 3.18 ± .03 GeV
-  = 164 ± 27 MeV

**opposite-sign pairs**
**same-sign pair bkgd**

- Run 2003 d-Au         200 GeV:
-                **Performance of the Muon Spectrometers**

- PHENIX ONLINE

**Yields**

- South

- North

**Invariant Mass [GeV/c]**

**Invariant Mass [GeV/c]**

**Yields**

**Yields**

**Yields**

- Di-muon invariant mass spectra

- PHENIX ONLINE

## PHENIX results

- Run -2 _final_ results:
**High pT pi0 (Au+Au @ 200 GeV): submitted to PRL nucl-ex/0304022**
**High pT pi0 (p+p @ 200 GeV): submitted to PRL hep-ex/0304038**
- Elliptic flow of identified particles (Au+Au @ 200 GeV): to be submitted to PRL
**J/Psi yields (Au+Au @ 200 GeV) to be submitted to PRC**
**J/Psi yields (p+p @ 200 GeV) to be submitted to PRL**
**p,pbar high pT enhancement (Au+Au @ 200 GeV) to be submitted to PRL**
- Run-2 _preliminary_ results:
- dN/dy and dE_T/dy  (Au+Au @ 200 GeV)
- Identified charged particle spectra and yields (Au+Au @ 200 GeV)
- Inclusive charged particle at high pT (Au+Au @ 200 GeV)
- phi -> KK (Au+Au @ 200 GeV)
- Event-by-event fluctuations (Au+Au @ 200 GeV)
- Di-Lepton continuum (Au+Au @ 200 GeV)
- Two-pion correlations (Au+Au @ 200 GeV)
- d and dbars (Au+Au @ 200 GeV)
- Run-3 _preliminary_ results:
**High pT pi0 (d+Au @ 200 GeV)**
**High pT inclusive charged particles (d+Au @ 200 GeV)**

-  Run 2002 p-p         200 GeV:
-                             **J/******** Invariant Mass Distribution**

**Invariant Mass [GeV/c]**

**Invariant Mass [GeV/c]**

- 	<pT>  = 1.80 ± 0.23 (stat) ± 0.16 (sys) GeV

-  Run 2002 p-p          200 GeV:  **J/********  p****T****  Distribution**

**p****T**** [GeV/c]**

**p****T**** [GeV/c]**

-  = 3.98 ± 0.62 (stat) ± 0.56 (sys) ± 0.41(abs) b

-  Run 2002 p-p        200 GeV:
-                                       **J/********  Rapidity Distribution**

**rapidity**

-  Run 2002 p-p        200 GeV:
-                  **Comparison with Previous Experiments**

## Run 2002 Au-Au         200GeV:                                  J/  Production Centrality Dependence

- Run 2002 Au-Au         200GeV:                                  **J/********  Production Centrality Dependence**

-    **0-20%**
**most central**
**  ****N****coll****=779**

-    **20-40%**
**most central**
**  ****N****coll****=296**

-    **40-90%**
**most central**
**    ****N****coll****=45**

**Proton**

- R.L. Thews, M. Schroedter, J. Rafelski Phys. Rev.
-  C63 054905 (2001): Plasma coalesence model
- for T=400MeV and ycharm=1.0,2.0, 3.0 and 4.0.

- L. Grandchamp, R. Rapp Nucl.
- Phys. A&09, 415 (2002) and
- Phys. Lett. B 523, 50 (2001):
- Nuclear Absorption+ absoption
- in a high temperature quark gluon
- plasma

- A. Andronic et. Al. Nucl-th/0303036

-   **Final**
**  ****to be **
**submitted **
** ****to PRC**

- Hadron Production at Large Transverse Momenta

- in colored “quark matter” partons expected to loose       significant energy via gluon bremsstrahlung
- attenuation or absorption of jets  “jet quenching”
- suppression of high pT hadrons
- modification of angular correlation
- changes of particle composition

## Collision Geometry --  “Centrality”

**15 ****fm****                         ****b                         0 ****fm**

**0                              N****part****                      394**

- Spectators

- Participants

- For a given b,
- Glauber model
- predicts Npart
- (No. participants)
- and Nbinary
- (No. binary collisions)

**0                              N****binary****                   1200**

## Quantify Nuclear Modification of Hadron Spectra 

- Quantify Nuclear Modification of Hadron Spectra

- <Nbinary>/inelp+p

- nucleon-nucleon
-   cross section

- 1. Compare Au+Au to nucleon-nucleon cross sections
- 2. Compare Au+Au central/peripheral

**Nuclear **
**Modification **
**Factor:**

- If no “effects”:
-      R < 1 in regime of soft physics
-      R = 1 at high-pT where hard
-                scattering dominates
- Suppression:
-      R < 1 at high-pT

*AA*

*AA*

*AA*

*AA*

*AA*

*AA*

## Run 2000 p-p        130 GeV:                                    Discovery of High pT Hadron Suppression at RHIC           

- Run 2000 p-p        130 GeV:                                    **Discovery of High p****T**** Hadron Suppression at RHIC           **

- o Charged hadron and neutral pion results
-    with independent systematic errors!
- o Extrapolation from UA1 as proton reference.

-  **High p****T  ****p-p and Au-Au ********0**** Results**

**Au-Au ****nucl-ex/0304022**

**p-p ****hep-ex/0304038**

- Run 2001/2002 p-p + Au-Au          200 GeV:

**Good agreement**
**with NLO pQCD**

**Data reach pT=12 GeV**

**R****AA****: High p****T**** Suppression**

- Run 2001/2002 Au-Au          200 GeV:

**Au-Au ****nucl-ex/0304022**

**Au-Au ****nucl-ex/0304022**

## p/ ~1 at high pT for central collisions

In peripheral collisions, p/ ~ 0.4

- In peripheral collisions, p**/** ~ 0.4

-       **Particle Composition at High p****T**

- Run 2001/2002 Au-Au          200 GeV:

##  Central to Peripheral Ratio for Protons and Pions

-  **Central to Peripheral Ratio for Protons and Pions**

- -  No apparent suppression in                 proton yields for 2 <pT<4 GeV/c
-   Different production mechanism for protons?

- Run 2001/2002 Au-Au          200 GeV:

##       Particle Composition at high pT

-       **Particle Composition at high p****T**

- (h++h-)/20 ~ 50% greater in central than peripheral at mid pT
- similar again for pT>5 GeV/c

- Central

- Peripheral

- Run 2001/2002 Au-Au          200 GeV:

- Run 2002/2003:d-Au and p-p at         200GeV

- p-p run goal:
- Access gluon polarization
- through double spin asymmetries
- ALL inclusive 0 production
- Required: 30% Polarization
-                  and Ldt=500nb-1

- ALL versus pT

## Successful Rotator Commissioning/Local Polarimetry

- Yellow

- Blue

- Rotators on--> radial polarization

- Rotators on --> vertical polarization

- See Kiyoshi Tanida’s talk Friday!

- Run 2002/2003:**High p****T ****Spectra in d-Au at        200 GeV**

**PHENIX PRELIMINARY**

**dAu min bias + **
**EMC trigger**

**p****T**** [GeV/c]**

**p****T**** [GeV/c]**

## Charged Hadrons RAA for d+Au: RdA

**Charged Hadrons R****AA**** for d+Au: R****dA**

-  Charged hadron are measured with tracking detectors in two independent arms
-  Cronin type enhancement relative to binary scaling

- Run 2002/2003 d-Au          200 GeV:

##                  0 RAA for d+Au collisions: RdA

-                  0 **R****AA**** for d+Au collisions: R****dA**

- Neutral pions are measured with 2 independent           Calorimeters – PbSc and PbGl

-  2 results agree within errors
-  Not suppressed relative to binary scaling

- Run 2002/2003 d-Au          200 GeV:

## “Cronin” enhancement more pronounced in the charged hadron measurement

Possibly a larger effect in protons at medium pT

- “Cronin” enhancement more pronounced in the charged hadron measurement
- Possibly a larger effect in protons at medium pT

**R****dA**** for charged hadrons compared to ********0**

- Run 2002/2003 d-Au          200 GeV:

## Neutron tagged p-A collisions

**Neutron tagged p-A collisions**

- Run 2002/2003 d-Au          200 GeV:

**p**

**n**

- ZDC

- Neutron tagged events are
- enhanced in ultra-peripheral
- collisions

- ZDC Energy Deposit

- FCAL Energy Deposit

## Comparison of ultra-peripheral events (<Ncoll>=3.6+/-0.4) 
                                  to minimum bias (<Ncoll>=8.5+/-0.7) 
No centrality dependence observed!

-                                   to minimum bias (<Ncoll>=8.5+/-0.7)
- No centrality dependence observed!

**Centrality Dependence of R****dA**

- Run 2002/2003 d-Au          200 GeV:

##     0 RAA Theory and Experiment for    central Au+Au and d+Au collisions

-     0 **R****AA**** Theory and Experiment for****    central Au+Au and d+Au collisions**

- Theoretical predictions:
- d+Au: I. Vitev, nucl-th/0302002 and private communication.
- Au+Au: I. Vitev and M. Gyulassy, hep-ph/0208108, to appear in Nucl. Phys. A; M. Gyulassy, P. Levai and I. Vitev, Nucl. Phys. B 594, p. 371 (2001).

- Run 2002/2003 d-Au          200 GeV:

- shadowing

- anti-shadowing

##     h+/- RAA Theory and Experiment for    central Au+Au and d+Au collisions

-     h+/- **R****AA**** Theory and Experiment for****    central Au+Au and d+Au collisions**

- Run 2002/2003 d-Au          200 GeV:

- without shadowing

## Summary

**PHENIX operates in design configuration**
**Successful d-Au and continuing p-p running**
**Wealth of results from Run-2 on Au-Au and p-p physics**
**Cronin like enhancement at high p****T **** in d-Au**
**We live in interesting times,**
**	****	****more results in the near future! **