Strangness production in p+p interactions at 20, 31, 40, 80 and 158 GeV/c from NA61/SHINE at the CERN SPS

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1 Strangness roduction in interactions at 2, 3, 4, 8 and 58 GeV/c from NA6/SHINE at the CERN SPS Szmon Pu lawski for the NA6/SHINE Collaboration Universit of Silesia, Katowice Setember 25

2 NA6/SHINE detector sstem

3 NA6/SHINE strong interactions rogram ArSc Statistical Model of the Earl Stage (SMES) "Ste" "Ste" "Horn" "Kink" "Horn" QGP HG QGP HG HG HG QGP HG ArSc Gaździcki, Gorenstein, Acta Phs. Polon. B3, 275 (999)

4 Results on interactions Data 2 GeV/c ( s = 6.2 GeV): GeV/c ( s = 7.7 GeV): GeV/c ( s = 8.8 GeV): GeV/c ( s = 2.3 GeV): GeV/c ( s = 7.3 GeV): events Results resented for hadrons roduced in inelastic collisions. Particle sectra: de/dx, tofde/dx and V identifications. he results are corrected for articles from weak decas (feeddown) and detector effects using MonteCarlo models. Out of target interactions are subtracted using events recorded with emt target.

5 Particle sectra 2 GeV /c 3 GeV /c 4 GeV /c 8 GeV /c 58 GeV /c π π K K

6 ransverse mass sectra at midraidit d 2 N/(m dm d) [(GeV/c 2 ) 2 ] NA6: at 58 GeV NA6 reliminar =23± MeV β =.9±.2 χ 2 /NDF=556/39 π ( 2.) π (.6) K (.) K (.5) (.5) Λ (.) d 2 N/(m dm d) [(GeV/c 2 ) 2 ] NA49: PbPb at 58A GeV/c =2± MeV β =.39±. χ 2 /NDF=67/69 π ( 2.) π (.6) K (.) K (.5) (.5) Λ (.) m m [GeV/c 2 ].5.5 m m [GeV/c 2 ] ransverse mass sectra are aroximatel exonential in interactions. In central PbPb collisions the exonential deendence is modified b the transverse flow.

7 Kaon at midraidit [/(GeV/c)] d 2 n dd 2 K X. < <.2 58 GeV/c 8 8 GeV/c 6 4 GeV/c GeV/c 2 2 GeV/c GeV/c [/(GeV/c)] d 2 dd n 2 K X. < <.2 58 GeV/c 8 8 GeV/c 6 4 GeV/c GeV/c 2 2 GeV/c Sectra fitted b: d 2 n d d = S 2 m K ex ( 2 m 2 K m K Fit allows to calculate: he inverse sloe arameter. Kaon multilicit in range not accessible b data. ).

8 Inverse sloe arameter Ste [MeV] 4 K [MeV] 4 K 2 PbPb AuAu SPS(NA6 ) WORLD() 2 PbPbAuAu SPS(NA6 ) WORLD() AGS SPS(NA49) AGS SPS(NA49) RHIC LHC(ALICE) RHIC LHC(ALICE) 2 s NN 4 [GeV] 2 s NN 4 [GeV] In collisions energ deendence of inverse sloe arameter of kaon exhibits raid changes like in PbPb interactions. Phs.Rev. C69 (24) 4493, SAR: Phs.Rev.C79:3499,29; ALICE: PLB 736 (24) 9627, Eur. Phs. J, C (2) 7:655

9 K π ratio Horn ( ) ( ) K /π.2 /π K.2. PbPb AuAu SPS(NA6 ) WORLD(, 4π). PbPb AuAu SPS(NA6 ) WORLD(, 4π) AGS SPS(NA49) AGS SPS(NA49) 2 RHIC LHC(ALICE) s NN 4 [GeV] 2 RHIC LHC(ALICE) s NN 4 [GeV] A shadow of the horn structure is visible in reactions but significantl reduced. Z.Phs. C65 (995) (π), Z.Phs. C7 (996) 5564 (K); BRAHMS: Phs.Rev.C72:498,25; ALICE: Eur. Phs. J, C (2) 7:655, PRL 9, 2523 (22)

10 K π ratio in interactions comarison to models ( ) ( ) K /π. /π K. NA6/SHINE HSD 2.5 UrQMD 3.3 UrQMD 3.4 Pthia 8 EPOS.99.5 NA6/SHINE HSD 2.5 UrQMD 3.3 UrQMD 3.4 Pthia 8 EPOS.99 [GeV] s NN.5 [GeV] s NN Models do not describe well NA6/SHINE data on interactions. High recision NA6/SHINE data allow for their significant imrovement. Vovchenko et al., PRC 9, 2496 (24), and rivate communication. Gavin Salam rivate communication UrQMD: Prog. Part. Nucl. Phs. 4 (998), J. Phs. G: Nucl. Part. Phs. 25 (999); HSD: Nucl. Phs. A 62, 449 (996), Nucl. Phs. A 644, 7 (998), Phs. Ret. 38, 65 (999); EPOS: Nucl.Phs.Proc.Sul.96,29, PYHIA: arxiv:4.32

11 Raidit sectra and mean kaons multilicities dn d K X 58 GeV/c 6 8 GeV/c 8 4 GeV/c GeV/c 2 GeV/c 2 dn d K X 58 GeV/c 8 GeV/c 4 GeV/c 3.9 GeV/c 2 GeV/c > < K > < K s NN [GeV] s NN [GeV]

12 Λ sectra in at 58 GeV/c

13 Λ sectra in at 58 GeV/c (/<Λ>)dn/dz.6 NA6 58 GeV/c.4.2 Ammosov et al. 69 GeV/c Chaman et al. 2 GeV/c Brick et al. 47 GeV/c Jaeger et al. 25 GeV/c LoPinto et al. 3 GeV/c z <Λ> NA6 58 EPOS.99 Ammosov et al. 69 GeV/c Chaman et al. 2 GeV/c Brick et al. 47 GeV/c Jaeger et al. 25 GeV/c LoPinto et al. 3 GeV/c Other data s (GeV) z = / beam Extraolation to the full hase sace b function: dn n dz = z2 2.69z 4 NA6/SHINE results are consistent with world data Other NA6/SHINE energies work in rogress

14 Summar data is unexectedl interesting. Even in the energ deendence of K /π and inverse sloe arameter exhibits raid changes in the SPS energ range. Do we see onset of deconfinement in interactions? High recision NA6/SHINE data resents a challenges for models and should allow their imrovement.

15 Backu

16 Kaons sectra ] [GeV/c dn dd K X at 2 GeV/c ] [GeV/c dn dd K X at 3.9 GeV/c ] [GeV/c dn dd K X at 4 GeV/c ] [GeV/c dn dd K X at 8 GeV/c ] [GeV/c dn dd K X at 58 GeV/c ] [GeV/c dn dd K X at 2 GeV/c ] [GeV/c dn dd K X at 3.9 GeV/c ] [GeV/c dn dd K X at 4 GeV/c ] [GeV/c dn dd K X at 8 GeV/c ] [GeV/c dn dd K X at 58 GeV/c

17 Comarison with NA49 results dn/d NA6 Preliminar π dn/d.5.4 NA6 Preliminar dn/d.6 NA6 Preliminar K NA6 NA NA6 NA NA6 NA dn/d.6 NA6 Preliminar π dn/d.5 NA6 Preliminar dn/d.5.4 NA6 Preliminar K NA6 (h ) NA6 NA NA6 NA NA6 NA

18 Analsis comarison [/(GeV/c)]. X.2 < <. [/(GeV/c)].5 K X. < <.2 [/(GeV/c)]. X K.2 < <.4 d 2 n dd.5 de/dx tofde/dx d 2 n dd..5 de/dx tofde/dx d 2 n dd.5 de/dx tofde/dx

19 ransverse mass sectra at midraidit d 2 N/(m dm d) [(GeV/c 2 ) 2 ] NA6: at 58 GeV NA6 reliminar =23± MeV β =.9±.2 χ 2 /NDF=556/39 π ( 2.) π (.6) K (.) K (.5) (.5) Λ (.) d 2 N/(m dm d) [(GeV/c 2 ) 2 ] NA49: PbPb at 58A GeV/c =2± MeV β =.39±. χ 2 /NDF=67/69 π ( 2.) π (.6) K (.) K (.5) (.5) Λ (.) m m [GeV/c 2 ].5.5 m m [GeV/c 2 ] ransverse mass sectra are aroximatel exonential in interactions. In central PbPb collisions the exonential deendence is modified b the transverse flow. fitted b Blast Wave Model: dn i m dm d = A i m K ( m coshρ )I ( sinhρ ) () from Schnedermann, Sollfrank, Heinz, PRC 48, 2462 (993)

20 Di in ISR energies [MeV] 4 K 2 PbPb AuAu SPS(NA6 ) WORLD() AGS SPS(NA49) RHIC LHC(ALICE) 2 4 s NN [GeV] [MeV] 4 K 2 PbPb AuAu SPS(NA6 ) WORLD() AGS SPS(NA49) RHIC LHC(ALICE) 2 4 s NN [GeV]

21 ISR deendence of fit range /HeData/74/d95x /HeData/74/dx ISR s = 23 = 53.7 ± 5.5 C = 59.4 ISR s = 3 (.2) = 45 ± 6. (.7) = 62 ± 5.6 (2.4) = 98 ± C = 5.7 ± 5. 4 C (..2) =45.8 ± (MeV) 2 K (MeV) 2 K ISR s=23 ISR s=23 ISR ISR s=3 s=45 ISR ISR s=3 s=45 ISR ISR s=53 s=63 ISR ISR s=53 s= (end of fit range).5.5 (end of fit range)

22 Strong interaction rogram (MeV) 2 8 5A GeV/c NA6 collected data 3A GeV/c 6 CC SiSi PbPb 4 2 NA49 NA6 future data BeBe ArSc XeLa µ (MeV) B

23 Statistical model of the earl stage

24 Assumtions

25 NA49 results