Transcript ALICE experiment at LHC (JINR participation)

ALICE
experiment at LHC
(JINR participation)
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Collaboration;
Detector Construction;
Physics tasks; Groups;
JINR team & JINR member-states
Computing;
Study of Quark-Gluon Plasma
is the main goal of
ALICE experiment
ALICE Collaboration
~ 1000 Members
(63% from CERN MS)
~30
Countries
~100
Institutes
Spain/Cuba
Romania
Japan Brazil
South Africa
Korea
USA
China
India Croatia
Armenia
Ukraine
Mexico
JINR
Italy
Russia
France
Netherlands
Hungary
~ 150 MCHF capital cost
(+ ‘free’ magnet)
ALICE
Collaboration statistics
Poland
Norway
TRD
800
MoU
600
TP
400
200
0
1990
LoI
1992
1994
1996
1998
2000
Germany
Slovak Rep.
Czech Rep.
1200
1000
UK
Greece
Sweden
2002
2004
Finland
CERN
Denmark
Size: 16 x 26 meters
Weight: 10,000 tons
TOF TRD
HMPID
ITS
PMD
Muon Arm
PHOS
TPC
ALICE Set-up
Very Large Dipole Magnet for Muon Spectrometer (9 x 7 x 3.5 m; 800 ton)
Transition Radiation Detector (assembly of supermodule)
1st Module of Photon Spectrometer (~ 4000 PWO crystals)
JINR team
Pavel AKICHINE, Vladimir APRAKSIN, Valentin AREFIEV, Valery ASTAKHOV, Anton
BALDIN, Victor BARTENEV, Boris BATYUNYA, Nicolay BLINOV, Mariana BONDILA,
Zemfira BORISSOVSKAIA, Yuri BUGAENKO, Vladimir BUDILOV, Zhelyu
BUNZAROV, Sergey CHERNENKO, Vladimir DATSKOV, Igor DODOKHOV, Valery
DODOKHOV, Leonid EFIMOV, Alexander EFREMOV, Oleg FATEEV, Oleg FEDOROV,
Anatoly FEDUNOV, Andrei GHEATA, Mihaela GHEATA, Oleg GOLUBITSKI, Lucia
JANCUROVA, Vladimir KADYSHEVSKY, Dmitry KALASHNIKOV, Vladimir KAPLIN,
Evgeny KISLOV, Evgeny KOSHURNIKOV, Boris KRASNOV, Mikalai KUTOUSKI,
Vladimir LIOUBOCHITS, Victor LOBANOV, Alexander MAKAROV, Alexander
MALAKHOV, Lyudmila MALININA, Henryk MALINOVSKI, Evgeny MATYUSHEVSKI,
Konstantin MIKHAILOV, Yuri MINAEV, Valery MITSYN, Ciprian MITU, Galina
NAGDASEVA, Alexander NESTEROV, Petr NOMOKONOV, Irina OLEX, Yuri
PANEBRATTSEV, Alexander PARFENOV, Maria PASYUK Vladimir PENEV, Victoriya
PISMENNAYA, Timur POTCHEPTSOV, Sergey SEMASHKO, Adrian SEVCENCO,
Galina SHABRATOVA, Alexei SHABUNOV, Igor SHELAEV, Alla SHKLOVSKAYA ,
Alexei SHURYGIN, Maria SHURYGINA, Yuri SHYSHOV, Nicolay SLAVIN, Lev
SMYKOV, Mais SULEYMANOV, Yuri TYATYUSHKIN, Martin VALA, Alexandre
VODOPIANOV, Vladimir YUREVICH, Yuri ZANEVSKIY, Sergey ZAPOROZHETS,
Nicolay ZHUKOV, Alexander ZINCHENKO, Oleg YULDASHEV
JINR contribution to ALICE
detector construction (1.7%)
Item
KCHF
• Muon Magnet
1025
• Photon Spectrometer
870
• Transition Radiation Detector 260
• Common Items
244
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Total:
2489
ALICE Physics Teams
ALICE PPR V1: J. Phys. G: Nucl. Part. Phys. 30, 1517 (2004);
V2: 32, 1295-2040 (2006)
➮ Heavy ion observables in ALICE
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Particle multiplicities
Particle spectra
Particle interferometry
Resonance production
Jet physics
Direct photons
Dileptons
Heavy-quark and quarkonium production
➮ p-p and p-A physics in ALICE
➮ Physics of ultra-peripheral heavy ion collisions
➮ Contribution of ALICE to cosmic-ray physics
Vector meson production: ( puzzle)
Predicted effect of partial chiral symmetry
restoration (M.Asakawa, C.M.Ko
LBL-35724, 1994). The shift of mass
depends from the temperature T.
SPS

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l n
(e+e-)
l - from early stage (QGP)
n - from late stage (freeze-out)
NA50/NA49: dN/dy(+-) / dN/dy(K+K-)  2 (1.8 - AMPT model);
NA50:T = 227±10 MeV , NA60: 253±2 MeV (228 MeV from the AMPT),
NA49:TKK = 305±15 MeV (267 MeV from the AMPT).
Simulation results for K+K- in Pb-Pb 106 central
events in ALICE using ITS, TPC and TOF.
(B.Batyunya, A.De Caro, G.Paic, A.Pesci. S.Zaporozhets. Phys.Part.Nucl.Lett. v2, N2 (125) 72, 2005;
B. Alessandro et al. ALICE PPR. J.Phys.G, V.32, p.1613)
n
S/B = 0.053 ± 0.0007
l
Fit parameters:
M=1019.6±0.04
width=4.3±0.1
The resonance peak after subtraction of
the background.
The double peak resolution possibility
in ALICE.
K+K- from 105 p-p events at 14 TeV obtained in GRID production
including JINR; (preliminary; B.Batyunya, M.Vala)
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S/B = 0.14
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Effective mass for K+K- pairs
and background from mixed events.
background
Fit (gauss):
M = 1.020+0.001 GeV,
 = 2.500  0.001 MeV
K+K- signal after background
subtraction.
Simulation results for dielectron decays of ,  and J/ in 107 central
Pb-Pb events using ITS, TPC and TRD in ALICE.
(B.Batyunya, M.Vala, S.Zaporozhets. Talk in First International Workshop on Soft Physics in
Ultrarelativistic Heavy Ion Collisions. Catania, 2006.)
S/B= (0.13 - 0.15)
Particle momentum correlations (as HBT effect in astronomy).
Due to the effects of quantum statistics (QS)
and final state interaction (FSI), the momentum
correlations of two or more particles at small relative
momenta in their center-of-mass system are sensitive
to the space-time characteristics of the production
process so serving as a correlation femtoscopy tool .
q = p1- p2 , x = x1- x2
w=1+cos qx
S is signal and B is background (from mixed events).
.
side
out  transverse
pair velocity vt
long  beam
The corresponding correlation widths are
usually parameterized in terms of the Gaussian
correlation radii Ri:
2
2
2
2
2
2
2
CF ( p1 , p2 )  1   ( Rout
qout
 Rside
qside
 Rlong
qlong
 2Rout
,long qout qlong )
Study of influence of particles identification and momentum resolutions effects
in ALICE detectors on correlation function (CF)
( L.Malinina, B.Batyunya, S.Zaporozhets. NUCLEONIKA 2004;49(Supplement 2)S99-S102 ).
The simulation has been done using HIJING model, GEANT-3 - ALIROOT packages
for ITS and TPC and Lednitsky’s algorithm for calculation of particle correlations.
TPC results for Qinv dependence of the CF,
CF = 1 + *exp(-Qinv2R2), for () pairs
at pt < 1 GeV/c of pions.
Fit parameters:
p0 = , p1 = R
100 %
Preliminary results for (K+K-) pairs
with taking into account the TPC tracking
efficiency and resolution.
Momentum correlations for two like-sign pions .
Predictions of Universal Hydro-Kinetic Model ( N.Amelin, R.Lednicky, L.Malinina et al.)
kt dependences of correlation radii
and parameter :
the triangle points - UHKM results,
the open points - STAR measurements.
The discrepancy for the  relates to an absence
of particle identification efficiency in the model.
Influence of resonance decays to the
correlation function parameters in
the UHKM model (preliminary).
Study of heavy quarkonia production in pA
collisions at the LHC energy
C.Mitu (Romania), A.Sevcenko (Romania), G. Shabratova, A.Zinchenko
pA
p>2GeV/c
p>1GeV/c
2005
2006
Study of heavy quarkonia production in pA
collisions at the LHC energy
cc contribution to the BGR
at p>1GeV/c
bb contribution to the BGR
at p>1GeV/c
2005
2006
Software development
• Comparison of the simulation results in frameworks
of Geant3 and Fluka transport codes into AliRoot:
A.Zinchenko, G.Shabratova
- The code of strip alignment in PHOS modules is
under insertion into AliRoot:
V. Pismennaya, T.Pocheptsov, G.Shabratova,
A.Zinchenko
- The update of PHOS code in AliRoot in accordance
with strict roles of C++. Graphics development in
ROOT: T.Pocheptsov
Alignment objects
Graphics development in ROOT (ROOT GL)
Box cuts
On TH3 the 2D contour is drawn
in real time on the cutting plane.
Possibility to paint TH3 using
iso-surfaces (iso-3D
contours).
RDIG sites for ALICE
Management and
financial support
ALICE GRID
Collaboration
Belarus,
Minsk
Romania,
ISS
Slovakia,
Koshice
IHEP
KI
JINR
LHE & LIT
PNPI
ITEP
INR
MEPHI
SINP
SPbSU
New participant
Resources statistics
• Resources contribution (normalized Si2K
units): 50% from T1s, 50% from T2s
– The role of the T2 remains very high!
–
JINR – 0.68% in 2006
–
RDIG -
~6% in 2006
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⇛
0.46% in 2007
7.2% in 2007
Requirements to resources at JINR in
2007-2010 from ALICE
CPU(kSi2k)
Disk(TB)
GRID Local GRID Local
2007
150
10
25-30 2
2008
300
20
50-70 5
2009
440
25
100
5
2010
650
25
200
5
CERN-INTAS grant
• INTAS Ref. No : 05-103-7484
• Project Title : Preparation for data
taking and distributed analysis for the
ALICE experiment at LHC.
• Proposal Coordinator:
Yves Schutz
(CERN)
Participation of young physicists & students in
ALICE JINR team
• Belorussia
• Slovakia
• Russia
1 person
2 persons;
3 persons;
Physicists from a number of JINR member-states
take part in ALICE physics via JINR:
Azerbaijan; Bulgaria; Mongolia;
Joint research with JINR member-states
physicists within ALICE groups:
Armenia; Poland; Romania; Russia; Ukraine
CONCLUSION
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Participation of JINR team in ALICE physics is based on:
1. Contribution to design and construction of particular ALICE subdetectors;
2. Long term participation in the physics and detector simulation;
3. Practical knowledge and experience in using of distributed
computing (GRIID) for data analysis.
JINR team has leading positions in some physics tasks. A few physics
groups were organized in ALICE .
Convener of one of these groups is JINR physicist Y. Belikov.
JINR has responsibility for the ALICE Computing in Russia.
JINR team presents scientific results on workshops & conferences.
Adequate funding for exploitation costs (setup and sub-detectors PHOS
and TRD) and travel have to be provided.
It is planned that the most of the data analysis carried by JINR, will be
done at Dubna. Computing power has to be increased by about 10 times.
Future plans in 2007-2008 years
 Simulation of pp and Pb-Pb collision from 0.9 TeV
till nominal LHC energies:
1.1. Vector mesons and quarkonia production
decaying to m+m- and e-e+ pairs with adequate
understanding of background conditions;
1.2. Study of direct photon and pi0 production
with suitable background environment
1.3. Momentum correlations (femtoscopy):
- Study of influence of particle identification and resonance
decays using the UHKM code .
 Participation in the data taking.
 Start the data analysis.
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