1 / 25

Stopping net proton rapidity spectra pbar/p vs s Kaon production K/  vs pbar/p

Energy dependence of stopping and the K/  ratio (BRAHMS data). Stopping net proton rapidity spectra pbar/p vs s Kaon production K/  vs pbar/p Kaon slopes vs pbar/p. Dieter Roehrich UiB. BRAHMS. NA49. AGS. From SPS to RHIC. Particle production increases ...

ketan
Download Presentation

Stopping net proton rapidity spectra pbar/p vs s Kaon production K/  vs pbar/p

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Energy dependence of stopping and the K/ ratio (BRAHMS data) • Stopping • net proton rapidity spectra • pbar/p vs s • Kaon production • K/ vs pbar/p • Kaon slopes vs pbar/p Dieter Roehrich UiB

  2. BRAHMS NA49 AGS From SPS to RHIC • Particle production increases ... • Projectile fragmentation region and central region • overlap at SPS • are well separated at RHIC • Antiproton/proton ratio at midrapidity resp. net-proton rapidity density change drastically with s

  3. (Net)-proton rapidity distribution • AGS energies • centrality dependence • energy dependence B. Back et al., E917 Collaboration. Phys. Rev. Lett. 86 (2001) 1970

  4. (Net)-proton rapidity distribution • SPS, 158 GeV/nucl., NA49- central collisions

  5. Rapidity distributions of produced hadrons at SPS • Rapidity distributions of both produced hadrons and net-protons peak at (or near) midrapidity

  6. Net-proton rapidity distribution dN dy • RHIC • central Au+Au • Npart=3578 BRAHMS, submitted to PRL, nucl-ex/0312023

  7. Stopping (1)

  8. Gaussians in pz: 2.03  0.16 2.00  0.10 Stopping (2) Net-baryon after feed-down & neutron corrections Gaussians in pz: 6 order polynomial Rapidity loss: (Npart= 357  10)

  9. Rapidity distributions at RHIC Rapidity distributions of • produced hadrons peak at midrapidity • net-protons peak at forward midrapidity

  10. SPS vs RHIC dn/dy net-protons pions RHIC: 35-40 80 forward rapidity (y4) at 200 GeV SPS: 41 100 midrapidity at 40 AGeV/c

  11. How to compare SPS and RHIC data? • use the antiproton/proton ratio: ratios at midrapidity (SPS) and at different rapidities (RHIC)

  12. Kaon production • K/ vs pbar/p • Kaon slopes vs pbar/p

  13. Fit: exponential Kaon spectra at RHIC AuAu 200 GeV AuAu 63 GeV BRAHMS preliminary Top 5% central collisions

  14. Kaon inverse slopes Top 5% central collisions

  15. K-/K+ vs pbar/p 62.4 GeV

  16. K/ vs rapidity at 200 GeV BRAHMS • Indication of divergence at large y

  17. K/ vs rapidity at 62.4 GeV BRAHMSpreliminary • Clear splitting of the ratio for positive and negative particles

  18. K/ vs s • The Horn

  19. RHIC 62.4 GeV BRAHMS preliminary K- - SPS- NA49 RHIC 200 GeV BRAHMS K-/- vs pbar/p • SPS data and RHIC data agree at same pbar/p ratio

  20. K+ + RHIC 62.4 GeV BRAHMS preliminary SPS- NA49 RHIC 200 GeV BRAHMS K+/+ vs pbar/p • SPS data and RHIC data agree at same pbar/p ratio

  21. Kaon slopes vs s • The Step

  22. Kaon slopes vs pbar/p SPS - NA49 RHIC 62.4 GeV BRAHMS preliminary T [MeV] RHIC 200 GeV BRAHMS 300 200 100

  23. Summary • Projectile fragmentation region and central region overlap at SPS and are well separated at RHIC • Antiproton/proton ratio at midrapidity changes drastically with s • Antiproton/proton ratio changes with rapidity at RHIC energies • Local systems (y1), characterized by the same pbar/p ratio, show identical K-/K+ and K/ ratios and kaon inverse slopes • The right side of the ’horn’ seems to be reproduced by going to forward rapidities at RHIC

  24. Pions: power law Kaons: exponential Protons: Gaussian Identified particle spectra Top 5% central collisions

More Related