ALICEexperiment at LHC(JINR participation)

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

~ 150 MCHF capital cost

(+ ‘free’ magnet)

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ALICE Collaboration statistics

LoI

MoU

TP

TRD

ALICE Set-up

HMPID

Muon Arm

TRD

PHOS

PMD

ITS

TOF

TPC

Size: 16 x 26 meters

Weight: 10,000 tons

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 teamPavel 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

__________________________________

Total: 2489

ALICE Physics TeamsALICE PPR V1: J. Phys. G: Nucl. Part. Phys. 30,

1517 (2004);V2: 32, 1295-2040 (2006)

➮ Heavy ion observables in ALICE 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)

SPS

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).

Predicted effect of partial chiral symmetry restoration (M.Asakawa, C.M.KoLBL-35724, 1994). The shift of massdepends from the temperature T.

l n

l - from early stage (QGP)n - from late stage (freeze-out)

(e+e-)

Simulation results for K+K- in Pb-Pb 106 central events in ALICE using ITS, TPC and TOF.

S/B = 0.053 ± 0.0007

Fit parameters:M=1019.6±0.04width=4.3±0.1

The resonance peak after subtraction of the background.

The double peak resolution possibility in ALICE.

n

l

(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)

K+K- from 105 p-p events at 14 TeV obtained in GRID production

including JINR; (preliminary; B.Batyunya, M.Vala)

background

S/B = 0.14

Fit (gauss): M = 1.020+0.001 GeV, = 2.500 0.001 MeV

Effective mass for K+K- pairsand background from mixed events.

K+K- signal after background subtraction.

S/B= (0.13 - 0.15)

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 inUltrarelativistic Heavy Ion Collisions. Catania, 2006.)

Due to the effects of quantum statistics (QS) and final state interaction (FSI), the momentumcorrelations 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.

Particle momentum correlations (as HBT effect in astronomy).

q = p1- p2 , x = x1- x2

out transverse pair velocity vt

side

long beam

The corresponding correlation widths are usually parameterized in terms of the Gaussian correlation radii Ri:

)2(1),( 2,

22222221 longoutlongoutlonglongsidesideoutout qqRqRqRqRppCF

.

w=1+cos qx

S is signal and B is background (from mixed events).

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 packagesfor ITS and TPC and Lednitsky’s algorithm for calculation of particle correlations.

TPC results for Qinv dependence of the CF,CF = 1 + *exp(-Qinv

2R2), for () pairs at pt < 1 GeV/c of pions.

Fit parameters:p0 = , p1 = R

100 %

Preliminary results for (K+K-) pairswith taking into account the TPC trackingefficiency and resolution.

Momentum correlations for two like-sign pions .Predictions of Universal Hydro-Kinetic Model ( N.Amelin, R.Lednicky, L.Malinina et al.)

The discrepancy for the relates to an absence

of particle identification efficiency in the model.

kt dependences of correlation radiiand parameter :the triangle points - UHKM results,the open points - STAR measurements.

Influence of resonance decays to thecorrelation function parameters inthe UHKM model (preliminary).

pA

Study of heavy quarkonia production in pA collisions at the LHC energyC.Mitu (Romania), A.Sevcenko (Romania), G. Shabratova, A.Zinchenko

2005

2006

p>1GeV/c p>2GeV/c

Study of heavy quarkonia production in pA collisions at the LHC energy

2005

2006

cc contribution to the BGR

at p>1GeV/cbb contribution to the BGRat p>1GeV/c

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

ALICE GRID Collaboration

JINR

LHE & LIT

Slovakia, Koshice

Romania, ISS

Belarus, Minsk

ITEP

INR

SINP SPbSU

MEPHI

PNPI

KIIHEP

Management and financial support

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 ⇛ 0.46% in 2007– RDIG - ~6% in 2006 ⇛ 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 1 person• Slovakia 2 persons;• Russia 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• Participation of JINR team in ALICE physics is based on:

1. Contribution to design and construction of particular ALICE sub-detectors;

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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