MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-0 Multiple scattering in EPOS: Implications for charm production K.W. in collaboration with B. Guiot, Iu. Karpenko, T. Pierog
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-1 D-meson multiplicity vs charged multiplicity N / < N > ALICE Significant N D1 deviation N D2 10 from the N D4 N D8 diagonal (linear increase) 5 in particular diagonal for large p t 0 0 1 2 3 4 5 6 7 N ch / < N ch > ALICE arXiv:1505.00664v1
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-2 PYTHIA 8.157
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-3 Already understanding a linear increase is a challenge! (Only recent Pythia versions can do) Even much more the deviation from linear (towards higher values)
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-4 Trying to understand these data in the EPOS framework: Two important issues: � Multiple scattering � Collectivity
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-5 EPOS: Based on multiple scattering and flow Several steps: 1) Initial conditions: Gribov-Regge multiple scattering approach, elementary object = Pomeron = parton ladder, s λ (CGC) using saturation scale Q s ∝ N part ˆ 2) Core-corona approach to separate fluid and jet hadrons 3) Viscous hydrodynamic expansion , η/s = 0 . 08 4) Statistical hadronization, final state hadronic cascade arXiv:1312.1233 , arXix:1307.4379
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-6 Initial conditions: Marriage pQCD+GRT+energy sharing (Drescher, Hladik, Ostapchenko, Pierog, and Werner, Phys. Rept. 350, 2001) (squared amplitude) For pp, pA, AA: A � � cut uncut � � σ tot = G −G cut P uncut P B � �� � dσ exclusive cut Pom : G = 1 s ) exp( R 2 s 2Im {FT { T }} (ˆ s, b ) , T = i ˆ s σ hard (ˆ hard t ) 2ˆ s λ Nonlinear effects considered via saturation scale Q s ∝ N part ˆ
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-7 A � � � � σ tot = i ) 2 + ( z A d 2 b d 2 b A i dz A ( b A i ) 2 ) i ρ A ( i =1 B � � j ) 2 + ( z B d 2 b B j dz B ( b B j ) 2 ) j ρ B ( j =1 �� � m k AB l k � � � � � � dx + x + . . . (1 − δ 0Σ m k ) k,µ dx − d ˜ k,λ d ˜ x − k,µ k,λ µ =1 m 1 l 1 m AB l AB k =1 λ =1 � 1 AB m k 1 � � k,µ , s, | � b + � π ( k ) − � G ( x + b A b B k,µ , x − τ ( k ) | ) m k ! l k ! µ =1 k =1 l k � � k,λ , s, | � b + � π ( k ) − � x + b A b B − G (˜ k,λ , ˜ x − τ ( k ) | ) λ =1 � α � A � � α B � � � � � � � x + x + x − x − 1 − k,µ, − ˜ 1 − k,µ − ˜ k,λ k,λ i =1 j =1 π ( k )= i π ( k )= i τ ( k )= j τ ( k )= j
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-8 Core-corona procedure (for pp, pA, AA): Pomeron => parton ladder => flux tube (kinky string) ✗ ✔ String segments with high pt escape => corona , the others form the core = initial condition for hydro depending on the local string density ✖ ✕ 2 core- η = -1.00 y (fm) dn/dp t dy pions x 100 corona 10 3 1.5 pPb 10 2 1 EPOS3.076 0.5 10 protons 0 1 -1 10 -0.5 corona -2 10 -1 core -3 10 -1.5 5.7fm 5 Pomerons pPb 5TeV 20-40% -4 10 -2 0 2 4 6 -2 -1 0 1 2 p t x (fm)
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-9 Core => Hydro evolution (Yuri Karpenko) Israel-Stewart formulation, η − τ coordinates, η/S = 0 . 08 , ζ/S = 0 ∂ ; ν T µν = ∂ ν T µν + Γ µ νλ T νλ + Γ ν νλ T µλ = 0 γ ( ∂ t + v i ∂ i ) π µν = − π µν − π µν γ ( ∂ t + v i ∂ i ) Π = − Π − Π NS NS + I µν + I Π π τ π τ Π � T µν = ǫu µ u ν − ( p + Π)∆ µν + π µν , � π µν NS = η (∆ µλ ∂ ; λ u ν + ∆ νλ∂ ; λ u µ ) − 2 3 η ∆ µν ∂ ; λ u λ � ∂ ; ν denotes a covariant derivative, � Π NS = − ζ∂ ; λ u λ � ∆ µν = g µν − u µ u ν is the projector or- � I µν 3 π µν ∂ ; γ u γ − [ u ν π µβ + u µ π νβ ] u λ ∂ ; λ u β = − 4 thogonal to u µ , π � I Π = − 4 3 Π ∂ ; γ u γ � π µν , Π shear stress tensor, bulk pressure � Freeze out: at 168 MeV, Cooper-Frye E dn d Σ µ p µ f ( up ) , d 3 p = equilibrium distr Hadronic afterburner: UrQMD Marcus Bleicher, Jan Steinheimer
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-10 Results Detailed studies of pt spectra and azimuthal anisotropies (dihadron corr., v n ) in pp, pA: � arXiv:1312.1233 [nucl-th]. Published in Phys.Rev. C89 (2014) 6, 064903. � arXiv:1307.4379 [nucl-th]. Published in Phys.Rev.Lett. 112 (2014) 23, 232301. � arXiv:1011.0375 [hep-ph]. Published in Phys.Rev.Lett. 106 (2011) 122004 � arXiv:1004.0805 [nucl-th]. Published in Phys.Rev. C82 (2010) 044904. In the follwing : An example of an asymmetric space-time evolution (high mult pp event, 7TeV)
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-11 3 η τ energy density [GeV/fm ] ( = 0.0 , = 0.10 fm/c) J 0 s 350 pp @ 7TeV EPOS 3.119 y [fm] 2 1.5 300 1 250 0.5 200 0 150 -0.5 100 -1 50 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-12 3 η τ energy density [GeV/fm ] ( = 0.0 , = 0.29 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 60 1.5 1 50 0.5 40 0 30 -0.5 20 -1 10 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-13 3 η τ energy density [GeV/fm ] ( = 0.0 , = 0.48 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 1.5 20 1 15 0.5 0 10 -0.5 -1 5 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-14 3 η τ energy density [GeV/fm ] ( = 0.0 , = 0.68 fm/c) J 0 s 9 pp @ 7TeV EPOS 3.119 y [fm] 2 8 1.5 7 1 6 0.5 5 0 4 -0.5 3 -1 2 1 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-15 3 η τ energy density [GeV/fm ] ( = 0.0 , = 0.87 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 1.5 4 1 3 0.5 0 2 -0.5 -1 1 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-16 3 η τ energy density [GeV/fm ] ( = 0.0 , = 1.06 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 2.5 1.5 2 1 0.5 1.5 0 1 -0.5 -1 0.5 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-17 3 η τ energy density [GeV/fm ] ( = 0.0 , = 1.25 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 1.4 1.5 1.2 1 1 0.5 0.8 0 0.6 -0.5 0.4 -1 0.2 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-18 3 η τ energy density [GeV/fm ] ( = 0.0 , = 1.44 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 0.9 1.5 0.8 0.7 1 0.6 0.5 0.5 0 0.4 -0.5 0.3 -1 0.2 0.1 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-19 3 η τ energy density [GeV/fm ] ( = 0.0 , = 1.63 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 0.6 1.5 0.5 1 0.4 0.5 0 0.3 -0.5 0.2 -1 0.1 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-20 3 η τ energy density [GeV/fm ] ( = 0.0 , = 1.83 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 0.45 1.5 0.4 0.35 1 0.3 0.5 0.25 0 0.2 -0.5 0.15 -1 0.1 0.05 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-21 3 η τ energy density [GeV/fm ] ( = 0.0 , = 2.02 fm/c) J 0 s 0.35 pp @ 7TeV EPOS 3.119 y [fm] 2 1.5 0.3 1 0.25 0.5 0.2 0 0.15 -0.5 0.1 -1 0.05 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-22 3 η τ energy density [GeV/fm ] ( = 0.0 , = 2.21 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 0.25 1.5 0.2 1 0.5 0.15 0 0.1 -0.5 -1 0.05 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-23 3 η τ energy density [GeV/fm ] ( = 0.0 , = 2.40 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 0.2 1.5 1 0.15 0.5 0 0.1 -0.5 0.05 -1 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
MPI at the LHC– 2015 – Trieste – Klaus Werner – Subatech, Nantes 0-24 3 η τ energy density [GeV/fm ] ( = 0.0 , = 2.59 fm/c) J 0 s pp @ 7TeV EPOS 3.119 y [fm] 2 0.16 1.5 0.14 1 0.12 0.5 0.1 0 0.08 -0.5 0.06 -1 0.04 0.02 -1.5 0 -2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 x [fm]
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