1. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 1 Semileptonic Decays Γ(Ke3) / Γ(pipi0) Γ(Kmu3) / Γ(pipi0) Γ(Kmu3) / Γ(ke3) Emphasis … numbers in the first draft of Semleptonics Paper Anne Dabrowski Northwestern University NA48/2 Collaboration Meeting 30 November 2005

2. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 2 Introduction Comments about numbers in the first draft of the paper –Form factor used was KTeV Pole for Ke3 and Kmu3 (In the October 2005 talk, the linear form factor was the nominal form factor used) –Acceptances –Table of Systematic errors –Results Additional Comments –Numerical Checks – can we trust PAW with weighted events? A preliminary comment the Σweights PAW v.s. FORTRAN –(important because systematic error due to form factor based on weighted events in the draft paper) For the final paper, MC events will be regenerated with the KTeV Pole MC … so no need for weights –Update on KLOE vs. Ginsberg + PHOTOS MC –Form factor normalisation –Acceptance comparison ke3 Conclusion Outline

3. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 3 Draft of the First paper released to Collaboration Mayda sent out the first draft of the Semileptonics paper on November 21 st I will present the numbers on that paper today. Comment on the paper are encouraged, and should be sent by Dec 5 th to – Alan Norton Alan.Norton@cern.chAlan.Norton@cern.ch – Heinrich Wahl – Mayda Velasco Ratio(ke3/pipi0); Ratio(kmu3/pipi0)

4. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 4

5. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 5 Choice of which form factor to use In the October 2005 Analysis meeting it was agreed by the collaboration, that is it better to use the Pole Model for the form factor. Numbers in the draft paper were recalculated, weighting the MC (generated with the linear form factors) by the ratio of the square of the form factors dependence in the matrix element Ratio(ke3/pipi0); Ratio(kmu3/pipi0) For the pole For the linear Values of parameters chosen: They are the only published results for both m s and m ν

6. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 6 Update Comparison radiative corrections Ginsberg + PHOTOS compared to KLOE

7. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 7 Input needed to extract the ratios Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 1.Acceptance 2.Particle ID efficiency 3.Trigger efficiency 4.Number of events in Data 5.Background substraction, done in both signal and normalisation

8. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 8 A. Dabrowski, October 27 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) Summary Table of inputs for the ratios

9. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 9 A. Dabrowski, October 27 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) Main Contributions to the background

10. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 10 Contributions to the systematic of ke3/pipi0 We have used Pole Form factor model as the reference, as measured by KTeV Form factor modelAcceptance Change in Quadratic (ISTRA 2004) Linear (PDG 2004 based on π 0 ) normalisation Difference when varying the m ν in the pole model by ±1 sigma of the measured values

11. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 11 Contributions to the systematic of kmu3/pipi0 Form factor modelAcceptance Change in Quadratic (ISTRA 2004) Linear (PDG 2004 based on π 0 ) normalisation Form factor model systematic also dominated by the quadratic. Reference parameterisation is KTeV pole measurement

12. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 12 Summary of results

13. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 13 Ratio kmu3/ke3

14. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 14 Summary of experimental Results Using the PDG 2004 value for the branching ratio of pipi0

15. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 15 To do before final paper goes out Re-generate the MC with the Chosen Form factor (Pole in this case) –Avoid using unnecessary weights and relying on PAW

16. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 16 Report on KLOE vs Ginsberg+PHOTOs MC ke3  from Cambridge meeting, showed ridges in KLOE/Ginsberg MC  After checks with C. Gatti (From KLOE), numerical solution solved. Still a slope in the Dalitz plane. This slope will be investigated. Cambridge Now i.e. October 2005 Recall: October 2005 Meeting

17. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 17 Report on KLOE vs Ginsberg+PHOTOs MC ke3 KLOE code revisited Form factor – linear BUT M π was put as the M π + Here plotted is the dalitz distribution for KLOE code with the two different pion masses in the denominator

18. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 18 Ratio KLOE code (charge/neutral pion mass) DIV Ginsberg + PHOTOS

19. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 19 Ratio KLOE code (charge/neutral pion mass) DIV Ginsberg + PHOTOS Still a difference between the two distributions, as a function of electron energy. Our selection is not sensitive to the acceptance change. Will pass this result onto the theorists

20. A. Dabrowski, November 30 2005 Ratio(ke3/pipi0); Ratio(kmu3/pipi0) 20 Conclusion First draft of the paper out on 21 st November This draft had the pole model of KTeV for the form factor Suggestion are welcome Before final paper goes out, MC will be re- generated with chosen form factor to avoid weighting the MC, at the compact level.