1 / 35

Strangeness Production in Ar+KCl Reactions with HADES

Detailed overview of the HADES Experiment conducted in 2005 at SIS/GSI, analyzing particle identification, vertex cuts, and results of particle production such as Kaons, Hyperons, and Mesons.

mcmullin
Download Presentation

Strangeness Production in Ar+KCl Reactions with HADES

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. Strangeness Production in Ar+KCl Reactions with HADES Experiment Overview • Data taking in September/October 2005 • Ar+KCl @ 1.756 AGeV • 10 TB raw data (4200 files) • 6.9*108 events used for analysis • Multiplicity 18 trigger (LVL1) • selected 35% most central reactions Analysis Overview • Particle identification of • using various information of the detectors Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  2. HADES Setup High Acceptance Di-Electron Spectrometer HADES @ SIS/GSI • Polar angle coverage: 18° < Q < 88° • Azimuthal angle coverage: 0° < f < 360° • 24 multi-wire drift-chambers in 4 planes • 2 time-of-flight walls (TOF/TOFino) • Superconducting toroid • RICH and preSHOWER for e+e--PID side view Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  3. PID using Time of Flight and dE/dx MDC TOF (44° < Q < 88°) Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  4. Beta vs. Momentum (Kaons) • K+ and K- - mesons can be • identified in the TOF region up to a • momentum of 1000 MeV/c • Due to the lower resolution in the • TOFino detector the identification • is limited to <600 MeV/c Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  5. Vertex-cuts • Inner drift-chambers are used • for vertex reconstruction • Primary vertex resolution: • Background reduction for • identification • Vertex position important for • mixed-event analysis Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  6. K0S-Mesons • 51.000 reconstructed -mesons • in the channel • S/B 1.0 • MeV/c2 Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  7. L-Hyperons • 145.000 reconstructed -hyperons • in the channel • S/B 0.3 • MeV/c2 Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  8. f-Mesons • 168 reconstructed -mesons • in the channel • S/B 1.1 • MeV/c2 Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  9. K0S Invariant Mass (mt) Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  10. L Invariant Mass (mt) Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  11. mt-spectra of L and K0S Boltzmann representation: Rapidity densitiy: Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  12. Kaons phase space distribution K+-Mesons K--Mesons Diploma thesis M. Lorenz Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  13. mt-spectra of charged kaons • Due to the lower resolution of the TOFino detector, only kaons • in the TOF-region were used for analysis • Still a phase-space coverage of one half of the rapidity distribution Diploma thesis M. Lorenz Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  14. f invariant mass (mt) and mt-spectra First measurement of a f-temperature at SIS energies! Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  15. Proton-Pion mt-spectra Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  16. Pion Rapidity Distributions Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  17. Proton Rapidity Distributions Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  18. Rapidity distributions of L-hyperons and K0S -mesons Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  19. Rapidity distributions of kaons Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  20. Rapidity distribution of f-mesons • Assumption of a symmetric and thermal distribution with width: • Variation of the data point inside the bin range gives systematic errors Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  21. Results of Particle Production Strangeness balance and S-production f/K--ratio Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  22. Phi-Meson Production f/K- -ratio becomes larger than 1 at SIS energies E. Bratkovskaya et al. Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  23. Teff as a function of particle mass Ni+Ni @ 1.93 AGeV (FOPI) Ni+Ni @ 1.93 AGeV (KaoS) All Ar+KCl @ 1.756 AGeV (HADES) Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  24. Summary • The MDC-dE/dx information was used for PID • and background suppression • 250.000 K+-meson, 145.000 L-hyperons, • 51.000 K0S-mesons, 6000 K--mesons and • 168 f-mesons were reconstructed • Corrected transverse mass spectra, rapidity- • and TB-distributions of K+, K-, K0S , L , f were presented • The production of S-hyperons was estimated from the • strangeness balance • The f/K--ratio is much higher compared to ultra-relativisitc • energies HADES can be used as a high resolution and high acceptance hadron spectrometer Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  25. Outlook Heavy strange resonances: Kaonic nuclear clusters: R. Kotte, FZ Rossendorf and HADES! Laura´s talk Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  26. HADES Collaboration G. Agakishiev8, C. Agodi1, A. Balanda3,e, G. Bellia1,a, D. Belver15, A. Belyaev6, A. Blanco2, M. Böhmer11, J. L. Boyard13, P. Braun-Munzinger4, P. Cabanelas15, E. Castro15, S. Chernenko6, T. Christ11, M. Destefanis8, J. Díaz16, F. Dohrmann5, A. Dybczak3, T. Eberl11, L. Fabbietti11, O. Fateev6, P. Finocchiaro1, P. Fonte2,b, J. Friese11, I. Fröhlich7, T. Galatyuk4, J. A. Garzón15, R. Gernhäuser11, C. Gilardi8, M. Golubeva10, D. González-Díaz4, E. Grosse5,c, F. Guber10, M. Heilmann7, T. Hennino13, R. Holzmann4, A. Ierusalimov6, I. Iori9,d, A. Ivashkin10, M. Jurkovic11, B. Kämpfer5, K. Kanaki5, T. Karavicheva10, D. Kirschner8, I. Koenig4, W. Koenig4, B. W. Kolb4, R. Kotte5, A. Kozuch3,e, F. Krizek14, R. Krücken11, W. Kühn8, A. Kugler14, A. Kurepin10, J. Lamas-Valverde15, S. Lang4, J. S. Lange8, L. Lopes2, L. Maier11, A. Mangiarotti2, J. Marín15, J. Markert7, V. Metag8, B. Michalska3, D. Mishra8, E. Morinière13, J. Mousa12, C. Müntz7, L. Naumann5, R. Novotny8, J. Otwinowski3, Y. C. Pachmayer7, M. Palka4, Y. Parpottas12, V. Pechenov8, O. Pechenova8, T. Pérez Cavalcanti8, J. Pietraszko4, W. Przygoda3,e, B. Ramstein13, A. Reshetin10, M. Roy-Stephan13, A. Rustamov4, A. Sadovsky10, B. Sailer11, P. Salabura3, A. Schmah4, R. Simon4, S. Spataro8, B. Spruck8, H. Ströbele7, J. Stroth7,4, C. Sturm7, M. Sudol4, A. Tarantola7, K. Teilab7, P. Tlusty14, M. Traxler4, R. Trebacz3, H. Tsertos12, I. Veretenkin10, V. Wagner14, H. Wen8, M. Wisniowski3, T. Wojcik3, J. Wüstenfeld5, S. Yurevich4, Y. Zanevsky6, P. Zumbruch4 Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  27. Backup slides Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  28. TOFino PID and RPC New RPC-detector (beam 2007) TOFino (18° < Q < 45°) Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  29. PID using TOF/TOFino-dE/dx TOFino (18° < Q < 45°) TOF (44° < Q < 88°) Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  30. Kaon Temperature and K-/K+-Ratio Diploma thesis M. Lorenz Teff and K+/K--ratio fits to the systematics of FOPI and KaoS results Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  31. Statistics of Reconstructed Particles Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  32. Mass-Spectra and PID using MDC dE/dx MDC I MDC II MDC III MDC IV particle track • Correction of the ToT-signal for various track topologies • Transformation from ToT to dE/dx, normalized to Bethe-Bloch • Truncated mean is calculated from all measurements of a track Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  33. PID using MDC-dE/dx MDC I MDC II MDC III MDC IV particle track • Correction of the ToT-signal for various track topologies • Transformation from ToT to dE/dx, normalized to Bethe-Bloch • Truncated mean is calculated from all measurements of a track Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  34. Primary Vertex reconstruction • New alignment procedure • for all detectors • Primary vertex resolution: • Important for mixed- event • technique Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

  35. Strangeness Production in Ar+KCl Reactions with HADES • HADES setup and experiment overview • Particle identification using various detectors • Reconstruction of • Transverse mass spectra and rapidity distributions • Particle multiplicities and results Alexander Schmah – GSI/FIAS/TU-Darmstadt Strangeness Workshop/GSI Darmstadt 2008

More Related