Pion-pion correlations in pp at sqrt(S)=900GeV In the EPOS model (ver. 1.90)

pp@900GeV 2*106 events generated by EPOS

Cut on pions: 0.05<p

T<2.0GeV/c

|y|<1

π+ π+ correlation function: QS weight (Coulomb switched off) 1D fit – superposition of two Gaussians:

R=1+ λ1exp(-R12Q

inv2) + λ2(-R

22Q

inv2)

R.Lednicky, T.Progulova Z.Phys.C 55, 295(1992)Look at: Total, “direct” and “secondary”(from decay) pions

K.Mikhailov, December 2009

Fathers of π+ in pp@900GeV

pp sqrt(s)=900GeV EPOS ver1.90

Code Decay Rate-2230 antiΣ-→nπ+ 0.89 %-2221 antiΔ- →nπ+ 1.53 %-2130 antiΛ →pπ+ 1.82 %-231 antiK*0→Kπ+ 2.86 %-1 direct pion 30.24 %20 K

s0 →π-π+ 7.49 %

111 ρ0 →π-π+ 14.63 %121 ρ+ →π0π+ 14.05 %131 K*+→Kπ+ 2.95 %220 η→π-π+π0 3.72 %221 ω→π-π+π0 11.95 %330 η'→ηπ-π+ 0.81 %1111 Δ++ →pπ+ 1.19 %

CF π+π+ in pp@900GeV

Primary and seconadary π+π+

Primary and seconadary π+π+

ρ, ω and K* in π+π+ CF

π+dir

π+ρ

π+dir

π+ω

π+dir

π+K*

3D fit and ProjectionsStandard 3D fit of EPOS pipi CF (2e6 events): Chi2/NDF = 1.1 Lambda = 0.27 +/- 0.01R_out = 0.84 +/- 0.02 R_side = 0.73 +/- 0.01 R_long = 1.42 +/- 0.02

Projections below:

Pion-pion correlations in pp at sqrt(S)=900GeV In the QGSM model

Malinina Liudmila, December 2009

pp@900GeV 3*106 events generated by QGSMQuark Gluon String Model tuned for pp LHC by UiO group (L. Bravina, E.Zabrodin et al)Cut on pions:

0.05<pT<2.0GeV/c

|y|<1

π+ π+ correlation function: QS weight and QS+Coulomb 1D fit – superposition of two Gaussians: R=1+ λ1exp(-R

12Q

inv2)

R=1+ λ1exp(-R12Q

inv2) + λ2(-R

22Q

inv2) R.Lednicky, T.Progulova Z.Phys.C 55, 295(1992)

R=1-λ-ξ+ λ KCoul (1+exp(-R2Q

inv2)) + ξKCoul(1+ a4/(a2+Q

inv2)2) A.Kisiel

Look at: Total, in progress: “direct” and “secondary”(from decay) pions

QS only !

QS + Coulomb

The work is under way.

Happy New Year !!!