Some hadrons with strangeness... Mesons: - - - K + = us, K = us: - PowerPoint PPT Presentation

Some hadrons with strangeness... Mesons: - - - K + = us, K = us: m = 493.677 MeV / c 2 - - - K 0 = ds, K 0 = ds: m = 497 .614 MeV / c 2 K*: m ≈ 892 MeV / c 2 - ϕ = ss: m = 1019.455 MeV / c 2 Baryons: Λ = uds: m ≈ 1115.683 MeV / c 2 - Σ + = uus, Σ 0 = uds, Σ = dds: m ≈ 1192 MeV / c 2 - Ξ 0 = uss; Ξ = dss: m ≈ 1320 MeV / c 2 - Ω = sss: m ≈ 1672 MeV / c 2 cf. Review of Particle Physics, Phys. Lett. B 667 (2008) 1

Particle yields in heavy-ion collisions plot taken Peter Braun-Munzinger’ s talk at the Blaizot-McLerran Fest (April 24, 2009)

Particle yields in heavy-ion collisions Particle yields at midrapidity in Pb-Pb collisions at = 7 .6 GeV √ s NN dN/dy s =7.6 GeV 2 NN 10 10 1 Data (NA49) − 1 10 Model, 2 /N =16.3/8 ! df 3 T=138 MeV, =380 MeV, V=1380 fm µ b + − − + − + K K p p " " # # $ $ % plot from Andronic, Braun-Munzinger & Stachel, Phys. Lett. B 673 (2009) 142

Particle yields in heavy-ion collisions Particle yields at midrapidity in Au-Au collisions at = 200 GeV √ s NN dN/dy s =200 GeV NN 2 10 10 Data 1 STAR PHENIX BRAHMS − 1 10 2 Model, /N =29.7/11 ! df 3 T=164 MeV, = 30 MeV, V=1950 fm µ b + − − + − + K K p p # # $ % & d d K* * * " " $ ' # plot from Andronic, Braun-Munzinger & Stachel, Phys. Lett. B 673 (2009) 142

Chemical freeze-out points T (MeV) 180 160 140 120 100 new fits (yields) 80 dN/dy 4 ! 60 parametrization 40 900 µ b (MeV) 800 2005 fits, dN/dy data ratios 700 yields 600 500 400 300 200 100 0 2 1 10 10 " s NN (GeV) plot from Andronic, Braun-Munzinger & Stachel, Phys. Lett. B 673 (2009) 142

Chemical freeze-out points vs. phase diagram plot taken Peter Braun-Munzinger’ s talk at the Blaizot-McLerran Fest (April 24, 2009)

“Strangeness enhancement” Wroblewski factor in elementary particle and heavy-ion collisions 2 � s ¯ s � λ s ≡ u � + � d ¯ � u ¯ d � 0.6 " S pp collisions 0.5 – collisions pp e + e - collisions 0.4 A+B collisions 0.3 0.2 0.1 0 2 3 10 10 ! s (GeV) plot from Becattini, Ga ź dzicki & Sollfrank, Eur. Phys. J. C 5 (1998) 143

“Strangeness enhancement” Yields in p-Be, p-Pb and Pb-Pb collisions at E lab = 158 A GeV plot from ALICE PPR, J. Phys. G 32 (2006) 1295

Particle yields in e + e - collisions Particle yields in e + e - collisions at = 91.2 GeV vs. “thermal models” √ s Multiplicities s =91 GeV Data 10 Model 1 -1 10 -2 10 i) no flavor 3 2 T=160 MeV, V=26 fm , =0.82, /N =595/28 " ! -3 df 10 s 10 1 -1 10 -2 10 ii) no flavor, c,b-subtracted data 3 2 T=168 MeV, V=18 fm , =0.66, /N =994/28 " ! -3 10 df s 10 1 -1 10 -2 10 iii) 5-flavor 3 2 T=170 MeV, V=16 fm , =0.66, /N =499/28 " ! -3 10 df s 0 + - + 0 + 0 0 ± 0 0 ± ’ 0 + - (1530) - (1520) (1285) (1420) - (1385) (1385) ’ , K K 0 & + 2 2 * ( * # # $ $ a % % 0 p ) ) ) ++ ' f K* K* f f 2 K + 1 1 ( ) ) * f f plot from Andronic et al., arXiv:0804.4132 [hep-ph]

Particle yields in e + e - collisions Particle yields in e + e - collisions at = 91.2 GeV vs. “thermal model” √ s Multiplicity (data) $ + 10 $ 0 e + e - ! s = 91.2 GeV %& K 0 K + 1 p & ’ -1 ' 10 ( ) +,0,- -2 T=164.6 ± 3.0 MeV 10 * - V=40.2 ± 5.7 fm 3 " s =0.648 ± 0.026 -3 # 2 =39/12 dof 10 + -3 -2 -1 10 10 10 1 10 Multiplicity (therm. model) Number of St.Dev. 4 2 0 -2 -4 K + K 0 & ) + ) 0 $ 0 $ + & , ) - * - p % ( ' + plot from Beccatini, Castorina, Manninen & Satz, Eur. Phys. J. C 56 (2008) 493

Particle yields in e + e - collisions Particle yields in e + e - collisions at = 91.2 GeV vs. “Unruh-Hawking √ s model” Multiplicity (data) $ + 10 $ 0 e + e - ! s = 91.2 GeV %& K 0 K + 1 p & ’ -1 ' 10 ( ) +,0,- " =0.1683 ± 0.0042 GeV 2 -2 10 * - m s =83.2 ± 4.0 MeV -3 # 2 =22/12 dof 10 + -3 -2 -1 10 10 10 1 10 Multiplicity (therm. model) Number of St.Dev. 4 2 0 -2 -4 K + K 0 & ) + ) 0 $ 0 $ + & , ) - * - p % ( ' + plot from Beccatini, Castorina, Manninen & Satz, Eur. Phys. J. C 56 (2008) 493