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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. Outline. Introduction
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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
Outline • 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
Draft of the First paper released to Collaboration • Mayda sent out the first draft of the Semileptonics paper on November 21st • I will present the numbers on that paper today. • Comment on the paper are encouraged, and should be sent by Dec 5th to • Alan Norton Alan.Norton@cern.ch • Heinrich Wahl <wahl@mail.cern.ch> • Mayda Velasco <Mayda.Velasco@cern.ch> Ratio(ke3/pipi0); Ratio(kmu3/pipi0)
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 For the pole For the linear Values of parameters chosen: They are the only published results for both ms and mν Ratio(ke3/pipi0); Ratio(kmu3/pipi0)
Update Comparison radiative correctionsGinsberg + PHOTOS compared to KLOE
Input needed to extract the ratios • Acceptance • Particle ID efficiency • Trigger efficiency • Number of events in Data • Background substraction, done in both signal and normalisation Ratio(ke3/pipi0); Ratio(kmu3/pipi0)
Summary Table of inputs for the ratios Ratio(ke3/pipi0); Ratio(kmu3/pipi0) A. Dabrowski, October 27 2005
Main Contributions to the background Ratio(ke3/pipi0); Ratio(kmu3/pipi0) A. Dabrowski, October 27 2005
Contributions to the systematic of ke3/pipi0 We have used Pole Form factor model as the reference, as measured by KTeV Difference when varying the mν in the pole model by ±1 sigma of the measured values
Contributions to the systematic of kmu3/pipi0 Form factor model systematic also dominated by the quadratic. Reference parameterisation is KTeV pole measurement
Summary of experimental Results Using the PDG 2004 value for the branching ratio of pipi0
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
Report on KLOE vs Ginsberg+PHOTOs MC ke3 Recall: October 2005 Meeting Cambridge • 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. Now i.e. October 2005
Report on KLOE vs Ginsberg+PHOTOs MC ke3 KLOE code revisited Form factor – linear BUT Mπ was put as the Mπ+ Here plotted is the dalitz distribution for KLOE code with the two different pion masses in the denominator
Ratio KLOE code (charge/neutral pion mass) DIV Ginsberg + PHOTOS
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
Conclusion • First draft of the paper out on 21st 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.