p + p Analysis

1. p + p Analysis K. Hagel Cyclotron Institute Texas A & M University BRAHMS Collaboration Meeting Oslo, Norway 12-May-2004

2. Short History of Ratio p+p story • Had what we believed to be almost complete analysis one year ago. • Preliminary results shown at DNP at MSU • Discovered bug in track projection when using INEL counters; fixed it • Re-did entire chain • Results seem to be “messed up” • Statistics, binning, other mistake • Quality of data • Following details analysis chain I used Brahms Collaboration Meeting

3. Cuts on the Data • INEL Vertex cut • Trigger cut (6 for FS, 3 for MRS) • Track-Vertex cut • Detector Fiducial cut • Swim status cut • Pid cut • Rapidity cut Brahms Collaboration Meeting

4. INEL Vertex Cut • MRS: -15 to 15cm • FS: -25 to 20cm • No bins in vtx in this analysis as this did not appear to change the results in a previous analysis. Brahms Collaboration Meeting

5. Track - Vertex Cut • Project track to beam • Take difference between track vertex and INEL vertex • Apply 2σ cut Brahms Collaboration Meeting

6. MRS Detector Fiducial Cut Brahms Collaboration Meeting

7. FS Detector Fiducial Cut Brahms Collaboration Meeting

8. Pid Cut • MRS • momentum dependent cuts in MRS • Centroids of p-dependent cuts adjusted run by run. • FS • Some momentum dependent cuts • Others straight where possible Brahms Collaboration Meeting

9. Run dependent centroids(MRS) Brahms Collaboration Meeting

10. MRS p-dependent windows Brahms Collaboration Meeting

11. Brahms Collaboration Meeting

12. FS pid windows Brahms Collaboration Meeting

13. FS pid windows Brahms Collaboration Meeting

14. FS pid windows Brahms Collaboration Meeting

15. FS pid Brahms Collaboration Meeting

16. FS pid Brahms Collaboration Meeting

17. Acceptance (Total) Brahms Collaboration Meeting

18. Acceptance (Accepted) Brahms Collaboration Meeting

19. Normalized Uncorrected Spectra(MRS) Brahms Collaboration Meeting

20. Normalized Uncorrected Spectra(FS) Brahms Collaboration Meeting

21. MRS Ratios Brahms Collaboration Meeting

22. FS Ratios Brahms Collaboration Meeting

23. y-dependence of ratios Brahms Collaboration Meeting

24. Summary • Have a complete analysis • Bjorn has comparisons of our results • Refinements to data analysis? • Towards publication • Should be fast although already slow • Towards spectra • Already have some preliminary spectra • They probably suffer from any problems that might be in here. Brahms Collaboration Meeting