NTRODUCTION : : Su INT Sumit Ba Basu su Lu Lund Un University - - PowerPoint PPT Presentation
NTRODUCTION : : Su INT Sumit Ba Basu su Lu Lund Un University ty, , Departm tment t of of Physics, , Divi Di vision of of Particle Physics, , Bo Box 118, 118, SE-221 221 00, 00, Lund, Sweden ema email: sumi umit.ba basu@
Sumit Ba Basu su
Lu Lund Un University ty, , Departm tment t of
, Di Divi vision of
, Bo Box 118, 118, SE-221 221 00, 00, Lund, Sweden ema email: sumi umit.ba basu@ u@cer ern. n.ch h
1
ALICE Expt. CERN)
(Wayne State University, USA) (Dec 2016 – Mar 2020) and Now,
(Lund University, Sweden) 2018 à Sumit V2.0
Chemical Freeze-out Kinetic Chemical potential (μ) Temperature (T)
Sources
( L. Stodolsky, Phys. Rev. Lett. 75, 1044 (1995) )
pT
dN/dpT a b
F(pt) ~ exp − pT Teff ⎛ ⎝ ⎜ ⎜ ⎞ ⎠ ⎟ ⎟
pT = pT
2 a b
∫
F(pt)dpT pTF(pt)dp
a b
∫
T
cv = C n = C VT 3
2
Ph.D.: Temperature Fluctuations
(GeV)
NN
S 10
2
10
3
10
〉 N 〈 C =
v
c
1 2 3 4 5 6 7 8
STAR Au+Au 0-5% STAR Cu+Cu 0-10% HRG HM HM via QGM QGM AMPT
(GeV)
NNS 1 10
210
310
∆ C =
vc
10 20 30 40 50 60 70
B µ , ch T = 0 B µ , kin T B µ , ch T = 0 B µ , kin T= VT ∆
Lattice prediction〉 N 〈 = ∆
Ph.D.: Multiplicity Fluctuations
3
ωch = hN2
chi hNchi2
hNchi = σ2 µ where, N is the charged particle multiplicity
kT = − 1 V ∂V ∂P # $ % & ' (
T
!" = $% < ' >% ) !*" = +,- < ' > ) !*"
kT expressed in fm3 GeV-1
Two-particle transverse momentum correlations
Sean Gavin et. Al PRL 97 162302 (2006) PRC 94 024921 (2016)
4
Two-particle transverse momentum correlations
Sean Gavin et. Al PRL 97 162302 (2006) PRC 94 024921 (2016)
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PLB Phys Lett. B, Volume 804 (2020) 135375 Ongoing further developments: Extend this study for pp and pPb and study the variation of G2 observable with dNch/dη Promising results, soon will be reported from ALICE, about System size dependence of G2 (Momentum Correlator)
Cumulant Normalized Cumulant R2 is a robust observable! Single track efficiencies cancel out of the ratio 4 different charge combinations for R2: (+ -), (- +), (+ +), and (- -) Charge Independent (CI) combinations Charge Dependent (CD) combinations R2CD is proportional to the Balance Function
C2(x1, x2) = ρ2(x1, x2) − ρ1(x1)ρ1(x2)
x ≡ {y,ϕ, pT} ρ(x) = 1 σ dσ dx
R2(x1, x2) = C2(x1, x2) ρ1(x1)ρ1(x2)
B(Δx) ≈ dNch dx R2
CD = dNch
dx 1 2 R2
+− − R2 ++ + R2 −+ − R2 −−
⎡ ⎣ ⎤ ⎦
CI = 1 2 LS +US
{ }
CD = 1 2 US − LS
{ }
LS = 1 2 (++) + (−−)
{ }
US = 1 2 (+−) + (−+)
{ }
Ge General D Defi finiti tion o
f Balance F Functi tions
For Charged particle, Signs (+) & (-) represents charge. For Λ’s being neutral particle, we define (+) for baryon number & (-) for antibaryon number. Similary, LS means same-type Baryonic number and US means opposite-type Baryonic number
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Conservation of quantum numbers.
charge produced at approx. the same space-time.
Understand / Probe
π± p(𝒒) : predominantly produced at late stage K± : predominantly produced at early stage
production
The width of the BF was initially proposed to be related to the time of hadronization. Bass, Danielewicz, Pratt PRL 85 2689 (2000)
7 # of quarks
Pratt PRL. 108, 212301 (2012)
8
Mo Motiva vation:
✓
h h Q
9
Mo Motiva vation: π K p Balance Functions
✓ ? ? ? ? ? ? ? ? ?
h π k p h π k P
Run I : Pb+Pb @ 2760 GeV
Q Q Q S Q B
10 # of quarks
Increasing Mass ( MeV) Centrality Charged Hadrons = Strange( )+ Non-Strange( ) Strange Meson = Kaon (K±) Non-Strange Baryon = Proton (p( ̅ 𝑞)) Non-Strange Meson = Pion (π±) 139 496 938 1. What about 𝝡 Strange Baryon ?? 2. Strange Baryons: Lambda Cascade Omega 3. Strangeness- Dependent Net Baryon?
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0.2 0.4 0.6
5 %
90 %
this thesis = 2.76 TeV
NNs Pb-Pb
p p
10.2 0.4 0.6
y) D B (
10 %
90 %
p K
1
0.1 0.2 0.3 0.4
p p
20 %
80 %
0.05 0.1
10 %
90 %
K p
10.1 0.2 0.3 0.4
10 %
90 %
KK
1
y D
0.05 0.1 0.15
20 %
80 %
pK
10.01 0.02
p p
20 %
80 %
0.02 0.04
20 %
80 %
Kp
1
0.05 0.1 0.15
pp
20 %
80 %
π± K± p(p) π± K± p(p)
2 40.2 0.4
5 %
90 %
p p
2 40.2 0.4
)
) (rad j D B(
10 %
90 %
p K
2 4 0.1 0.2 0.3
20 %
80 %
p p
2 40.05
10 %
90 %
K p
2 40.05 0.1 0.15
10 %
90 %
KK
2 4
(rad) j D
0.05 0.1
20 %
80 %
pK
2 40.01 0.02
20 %
80 %
p p
2 40.01 0.02 0.03
20 %
80 %
Kp
2 4 0.05 0.1
20 %
80 %
pp
π± K± p(p)
Δy Δɸ(rad)
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20 40 60 80
0.4 0.6 0.8 1
y D
s
±p
p
±K
p ) p p(
p
±p
K
±K
K ) p p(
K
±p
p p(
±K
p p( ) p p(
p p(
= 2.76 TeV
NNs ALICE Pb-Pb
20 40 60 80
1 1.5
j D
s
20 40 60 80
Centrality (%)
0.2 0.4 0.6
B
Y
BF Widths and Integrals
0.5 < pT(p(p)) < 2.5 GeV/c 0.2 < pT(π±, K±) < 2.0 GeV/c
STAR PRC 82, 024905 (2010)
Au-Au @ 200 GeV 0.2 < pT < 0.6 GeV/c
ALICE, PRC 88, 044910 (2013)
13
Mo Motiva vation:
✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
h π k p h π k P
Run I : Pb+Pb @ 2760 GeV Run II : Pb+Pb @ 5020 GeV
Q Q Q S Q B
Work in Progress
B S Λ Λ
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Re Resu sults: s: R2 R2 Same Baryon/Strange
Ref: Eur.Phys.J. C77 (2017) 569 p+p @ √s =7 TeV
60-80% 30-40% 0-10%
R2(x1, x2) = C2(x1, x2) ρ1(x1)ρ1(x2)
Opposite Baryon/Strange
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Re Resu sults: s: B
Two Wave quark Production??? Radial Flow effect???
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and make a connection Between Balance Function & Per Trigger Yield analysis
QGP(EPOS) approach to regular PYTHIA MPI model(Lund string model), Strange (Rope Hadronization framework/ Flavour Ropes) and Flow(Rope Hadronization framework/ String shoving)
Λ# Λ
We want to study the Quark Gluon Plasma (QGP) We measure the correlations between identified particles B1 Ø These collisions produce “large” systems
called the Quark-Gluon Plasma (our universe up to a few µs after BB) Ø nearly perfect fluid (surprise!) Ø Briefly ~100,000 times hotter than the core of the Sun. Ø Thousands of particles are produced in every event.
p — particle momentum pT — transverse momentum φ — azimuthal angle θ — polar angle η — pseudorapidity y — rapidity
pT
2 = px 2 + py 2
η ≡ −ln tan(θ 2) ⎡ ⎣ ⎢ ⎤ ⎦ ⎥ = 1 2 ln p + pz p − pz y = 1 2 ln E + pz E − pz Transverse plane Lorentz invariant
B2
N1 N2
B3
27 kilometers (17 mi) in circumference ~ 100 meters (328 ft) underground Lead ions are accelerated to more than 99.9999% of the speed of light and collide.
B4
Excellent particle identification capability
π± K± p(p) Purity >97 % >95% ~ 94%
B5
B6
An Analysi ysis s Details: s:
Runlist MagFieldMinus: Runlist MagFieldPlus:
Data sets LHC18q & LHC18r pass1
Event SelecLon: V0M, |Vz| < 10 cm. Pile up cut Track SelecLon: TPC Only Tracks ( filterBit= 128 )
0.6 < pT< 3.6 GeV/c nCluster >=70 0 ≦ ɸ ≦ 2π
Ne New w
RunList_LHC18q_pass1_CentralBarrelTracking_hadronPID.txt SSD SPD SDD V0 TPC TOF T0 ZDC 126 runs RunList_LHC18r_pass1_CentralBarrelTracking_hadronPID.txt SSD SPD SDD V0 TPC TOF T0 ZDC 90 runs
B7