Analysis strategy of high multiplicity data Toshiyuki Gogami 24/Feb/2011.
High Multiplicity Study
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Transcript of High Multiplicity Study
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High High Multiplicity Multiplicity
StudyStudyE.Kokoulina, A.Kutov for SVD-2 Collaboration JINR, Russia & GSTU, Belarus
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OUTLOUTLINEINE IntroductionIntroduction
Gluon Dominance Model (eGluon Dominance Model (e++ee--, , pp, pA, pp)pp, pA, pp)
“ “Thermalization” project status Thermalization” project status
OutlookOutlook
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IntroductiIntroductionon
We use the unified approach to the multiplicity description at HEP. It is based on essentials of QCD and on the main experimental phenomena in multiparticle dynamics.
We are interested the high multiplicity (HMHM) region: n > n(s).
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- annihilation
ee
proton (nucleus) collisionsproton-antiproton- annihilation
pQCD & hadronizationSoft Photons
V. Kuvshinov, E.K. Acta Phys.Polon. B13 (1982).
IntroductiIntroductionon
THERMALIZATION project
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ee
First stage (cascade): a) gluon fission; b) quark bremsstrahlung; c) quark pair creation.
hadronsgqqqZee ?),()( 0
Second stage (hadronization): BD
.)1(1PN
p
hpH
p zN
nQ
Convolution: of two stages.
!
)1)...(1(pk
p
p
m
p
pppm km
k
km
m
m
mkkkP
quark fission -> NBD
Gluon Dominance Model Gluon Dominance Model (GDM): e(GDM): e++ee-- annihilation annihilation
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Pn in -annihilation at 22 (TASSO) and 161 GeV (OPAL) ; H(q) at 161 GeV.
ee
E. K. Minsk, NPCS (2002)]; ISMD32,2002.
22 GeV
Pn 161
GeV
Pn H(q)
161 GeV
GDM: eGDM: e++ee-- - annihilation - annihilation
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nn nn
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s s
hgn
)( hgg nN - maximal (average)
multiplicity of hadrons from one gluon while its passing through of hadronization is constant -> fragmentation mechanism of hadronization (one to one)
gluon hadronization is softer than quark one:
2.~/ qg NN
gN
GDM: eGDM: e++ee-- - annihilation - annihilation
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After an inelastic collision of two protons the part of energy are converted into the thermal (the dissipating energy) and one or few gluons become freeGluons may give cascadeSome of gluons (not of all) leave Quark-Gluon System (QGS) – are evaporated and are converted to hadrons.
1st
stage
2nd
stage
GDM: pp - interactionsGDM: pp - interactions
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Our model study had shown: quarks of initial protons are staying in leading particles (from 70 to 800 GeV/c). Multiparticle production (MP) is realized by gluons*). We name them active ones. _________________________________________*The dominance role of gluons at multiparticle production (MP) was proposed S.Pokorski and L. Van Hove (1975), P. Carruthers (1984).
GDM: pp - interactionsGDM: pp - interactions
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1. Scheme with the branch of gluon in QGS (TSMB)
2. Scheme without the gluon branch (TSTM)
E.K. and V.Nikitin. 7th Int. school-seminar The actual problems of Microworld Physics, Gomel, Belarus. 1 (2004)
GDM: pp - interactionsGDM: pp - interactions
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MD of active gluons at the moment of impact (Poisson)
MD of branch gluons (Furry) for the first scheme
MD at the hadronization stage (BD)
GDM: pp – interactions GDM: pp – interactions (scheme with branch) (scheme with branch)
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- ratio of evaporated gluons to all active ones;
gluon hadronization parameters on second stage;
)5.0(~Nn h ,
N ~40. This value is very likely to the number of partons in the glob of cold QGP, which leads to production of soft photon excess. P.Lichard & L.Van Hove. Phys.Let. B245 (1990) 605.
GDM: pp – interactions GDM: pp – interactions (scheme with branch)(scheme with branch)
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E.K. Acta Phys.Polon. B35(2004)295
pp –pp – interactions (scheme interactions (scheme without branch)without branch)
After evaporation gluons leave QGS and fragment to hadrons. MD is convolution Poisson and BD
69 GeV/c 800 GeV/c
chn chn
nPnP
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p, GeV/c
Mg
N
69 2.48 +/-
0.20
6 4.24 +/-.13
1.63 +/-0.12
~2
102 2.75 +/
0.08
8 3.13 +/-.56
1.64 +/-0.04
2.2
205 2.82 +/- 0.20
8 4.50 +/-.10
2.02 +/-0.12
2.0
300 2.94 +/- 0.34
10 4.07 +/-.86
2.22 +/-0.23
9.8
405 2.70 +/-.30
9 4.60 +/-.24
2.66 +/-0.22
16.4
800 3.41 +/-2.55
10 20.3 +/-10.4
2.41 +/-1.69
10.8
m hn 2
pp –pp – interactions (without interactions (without branch)branch)
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Hadronization Hadronization MechanismsMechanisms recombination mechanism
clan as independent intermediate gluon sourceqq
qqq
Recombination:
1Meson
Baryon
Fragmentation:
1Meson
Baryon
B.Muller [nucl-th/0404015]
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Mean multiplicity of π0 versus the number of nch
2
1
2
1
/)()(0
n
nn
n
nnnchtotnch
tot tot
tottotPnnPnn
pp – interactionspp – interactions (neutral)(neutral)
MD of π0 at 69 Gev/c Limits to max charged, neutral & total multiplicities (26, 16, 42).
gluon hadronization parameters for π0
Centaur (yes, HM region), AntiCentaur (no)
particle number limits
V. Grishin. Phys.El.Part.and At.Yad. 10 (1989)689.
)(0 chnn
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62 GeV
E.K., Nikitin V. et al. ISHEPP2004.
.1!
1!
)(
)2(22
22
2
22
)2(2
2
1
11
2
2
2
2
22
1
1
1
1
11
nNmhnh
nNm
M
m
mm
nNmhnhnNm
M
m
mm
n
N
n
N
nC
m
me
N
n
N
nC
m
mesP
14.23.3 hn
)1( 21
.13/9/,8.1~/
,25.015.1,03.059.32
21
21
ndf
mm
1 2
pp – interactionspp – interactions (ISR, 30-60 GeV)(ISR, 30-60 GeV)Clan
(cluster) superposition consisting from one, two (or more) gluon fission
Soft ( ) & semi-hard ( ) components, and so on.
Pn
n
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GDM h/ for pp: 70 GeV/c = 1.19+/-0.25 ,,, 800 GeV/c = 1.49+/-0.33 … 62 GeV ~ 1.6 ( ).
PHEN
IXh
hch
h
ch
n
n
nsmh
sn
sn
000 2
1
)(
1)/(
)(
2/)(
076.10 hn
pp(nucleus) – pp(nucleus) – interactions (h/interactions (h/ ratio) ratio)Au-Au 200 GeV/N, peripheral (60-92%).
GDM: PHENIX. Nucl.Phys.A757(2005).
the dominance of active gluon plenty in nucleus central collisions leads to the new kind matter formation –QGP
agreement with h/ ratio
pp
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1.0)(,40,4 nTnmbmb inin
Soft photons Soft photons (SP excess)(SP excess)
Measured SP:
01.0,/1.0 xcGeVptσ(SP) are 5-8 times larger than expected ones from QED.
Assumption: QGS or excited new formed hadrons set in almost equilibrium state during a short period. That is why we use the black body emission spectrum:
.
1
8 3
3
T
h
ecd
dn
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383
10112.4/)()(725.2,2
244.0)(
mVTnMVBKThc
kTVTn rr
3
3
3968
3
101010112.4/)()(,)()(
fm
T
TVTnT
T
TTnTn
rrr
)()(3 TLnTL L(fm)
L(fm)
10 11. 30 3.5
15 6.9 40 2.6
25 4.1 50 2.0
tp tp2 tppT
M.Volkov,E.K., E.Kuraev. Part. & Nucl. Let., 5 (2004)122
Soft photons Soft photons (SP excess)(SP excess) The number of SP is estimated by MVB
density ρ(T )=n(T)/V:
estimation of SP emission region
SP excess is the sign of hadronization
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pp – annihilation pp – annihilation (experiment)(experiment)
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J.Rushbrooke & B.Webber. Phys.Rep. C44(1978)1.)(sn
2f
)( 2GeVs
22 )1( nnnf
)(sn
n
)()( pppp nnn
32, 100 GeV/c
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mNhm zNnzQzmQ )1(/1),1(),(
GDM: pp – GDM: pp – annihilation annihilation
.0/)(~ 22 Nnmf h
Experiments (10-100 GeV/c): a tendency to the production of leading mesons. f2 behavior explanation. The simple scheme with appearance at first moment of m active gluons. GF and f2 :
E.K. AIP. 828 (2006) 81
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GDM: pp – GDM: pp – annihilation annihilation
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GDM includes intermediate quark topologies at the initial stage making only from valent quarks (“0”-, “2-”) or valent and vacuum ones (“4-”, “6-”). MD are superposition of them.
p
p
+ +0 00
0 + +
+ + + +…
(“0”)
(“2”)
(“4”)
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,/ nnnP
.05.0:40:15:: 420 ccc
.5.1~/,61.074.1
,18.036.32 ndfn
mh
GDM: pp – GDM: pp – annihilationannihilation
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14.75 GeV/c
mNhM
m
Gm
mNhM
m
Gm z
N
nPzcz
N
nPczQ )1(1)1(1)(
202
20
.)1(14
44
mNM
m
hGm z
N
nPzc
intermediate topology superposition
hadronization predominance at annihilation
Pn
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Scientific programme: multiparticle dynamics study in p+p(A) interactions with HM (n>20) at IHEP U-70.
SVD-2 Collab.: Belarus, Czech Republic, Russia, Slovak Republic, Ukraine
project project “THERMALIZATIO“THERMALIZATION”N”
SVD-2 setup
V.V.Avdeichikov et al. JINR-P1-2004-190, Proposal ”THERMALIZATION”.
Micro strip VD, 10000 channels.
Drift tubes tracker, 2400 channels
Magnetic spectrometer
DeGa
Č
target
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mm
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Liquid hydrogen target
Trigger scintillation hodoscope (“camomile”) for the registration of rare events with HM:
20 elements: triangle h=18, thickness 1.8 mm
Project Project “THERMALIZATI“THERMALIZATIONON
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project project “THERMALIZATIO“THERMALIZATION”N” Search for & new
collective phenomena study:
1. BEC of identical particles.
2. Ring events (Cerenkov gluon).
3. Soft photon cross section.
4. Grouping of secondary.
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project project “THERMALIZATIO“THERMALIZATION”N”
1) M.I.Gorenstein & V.V.Begun, BITP, Ukraine [hep-ph/0611043]:at HM the experimental manifestation of BEC may be founded by the sharp increase of neutral meson multiplicity fluctuations at fixed total multiplicity.
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project project “THERMALIZATIO“THERMALIZATION”N”2) RUN
2002: Ring event search [Seminar NPCS,Minsk,2006]. 4) RUN 2002: the indication to the grouping of secondary in the certain direction [Hep-ph/0612364]
Preliminary
Preliminary
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project project “THERMALIZATIO“THERMALIZATION”N”
MD in pC, pSi and pPb
RUN 2002
pC
pSi pPb
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project project “THERMALIZATIO“THERMALIZATION”N”Alignment taskAlignment task of detectors is an essential step
in the track reconstruction:
beforeafter
2006 data
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project project “THERMALIZATIO“THERMALIZATION”N”
Z, mm
X, mm
Y, mm
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““THERMALITHERMALIZATION”ZATION”
n=n=2222
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““THERMALITHERMALIZATION”ZATION”
Multiplicity distributions for X and Y planes (n_beam<5)
Integrated MD for X, Y planes
Preliminary
Preliminary
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• Data pA (Si,C, Pb) 2002 run will be study
• A set of pp data in 2007-2009 runs will be obtained.
• We expect interest phenomena in the HM region will be got.
OutlOutlookook
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