PHENIX Computing Center in Japan [CCJ]

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PHENIX Computing Center in Japan [CCJ]
S.Yokkaichi, T. Ichihara, Y. Watanabe, S. Kametani, A. Kiyomichi, H. En’yo and Y.Goto (RIKEN, RBRC)

RIKEN CCJ Project• Regional computing center in Japan for BNL-RHIC experiment especially for PHENIX collaboration.
• CCJ serves for RHIC physics activity in Japanese and Asian scientists.
• Analysis of large scale data and simulation.
••

RIKEN-CCJ http://ccjsun.riken.go.jp/ccj//
CPU performance : Pentium III/4 CPU•Use CPU resource of RIKEN Super Combined Cluster System (RSCC)•210 (0.7~2.0GHz, CCJ) +256 (3.06GHz, RSCC) CPUs
• Disk Storage : 53 TB• HPSS (High Performance Storage System)•Tape Storage: 800 TB ( = 4,000 tapes, expandable to 1.2 PB)•4 tape/disk movers / Disk cache 8TB

PHENIX Expe rim e n t http://www.phenix.bnl.gov/- Collisions of polarized protons and heavy ions are delivered at
BNL-RHIC.
- Understand the spin structure of the proton through polarized
proton collisions.Search for quark gluon plasma, a state thatexisted at an early stage after Big Bang.
- 550 collaborators from 13 countries, 62 institutions(as ofMar.05).
- Amount of DATA ~500TB/year

Data of High-energy nuclear phyics experiment

5TB/day = 60MB/sec

Long Island, NYInternet
RIKEN-CCJWako,Japan

Data transfer between RIKEN and BNL byinternet• In 2005 (PHENIX run5), the raw data were transferredusing GridFTP.
• Transfer is performed simultaneously witharchiving to HPSS at BNL.
• 260 TB of raw data (150K files ) were transferred in80 days (typically 60MB/sec was achieved).
• Analysis of these data was taken for 90 days by
RSCC 200 CPUs and 90 TB of summary data(DST/nDST) were produced.
• 20 TB of produced data (nDST) were also sent
back to BNL.

Relativistic Heavy Ion Collider
Brookhaven National Lab.
PHENIX event display
Au+Au √s = 200GeVPHENIX Experiment
Study of the Quark-Gluon Plasma
with heavy-ion collisions

Study of the Proton Spin Structurewith polarized-proton collisions

In this schematic illustration two gold nuclei collide and give riseto thousands of quarks and gluons, which then equilibrate into ahot cauldron of matter, the quark-gluon plasma. As this plasmacools, it condenses into the ordinary particles seen by thedetectors.

Proton consists of threequarks, sea quarks andgluons. To investigateinIn this schematic illustration two the spin of gluon
polarized protons collide and obtain proton, the experiment
important data to understand the spin of using polarized-proton
is requiered.
the proton.

Data transferred
Data analyzed

Data produced

PHYSICS RESULTS
The Cover of Physical Review Letters

Measurement of the double helicity asymmetry ininclusive mid-rapidity neutral pion production forpolarized proton-proton collisions.This is the first of aprogram to study the longitudinal spin structure of theproton, using strongly interacting probes, at collider
energies. In perturbative QCD, ALL is directly sensitive
to the polarized gluon distribution function in theproton through gluon-gluon and gluon-quark subprocesses. The observed asymmetry is small andconsistent with a standard gluon polarization model.

Physical Review Letters 88, 022301 (2002)

Plotted as a function of transverse momentum (pT) is the ratio, RAA, of themeasured yield of charged and neutral pions in Au-Au collisions to the yieldthat would be expected based on an extrapolation of proton-proton collisions.
The PHENIX results and measurements taken at lower energies at the CERN
SPS are qualitatively different. At RHIC higher pT seems to be depleted,which was predicted assuming an energy loss of partons in dense matter.