1 / 4

Current status

Current status. ~ 4fb -1 , ~ 50000 dileptons at the end of the analysis The statistical error on m (0.0158 pb -1 ) is smaller than the total error of PDG 98 (0.019 pb -1 ) !!!. The value of m will be kept hidden as far as all the systematic effects haven’t been understood.

macon
Download Presentation

Current status

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. Current status • ~ 4fb-1 , ~ 50000 dileptons at the end of the analysis • The statistical error on m (0.0158 pb-1)is smaller than the total error of PDG 98 (0.019 pb-1) !!! The value of m will be kept hidden as far as all the systematic effects haven’t been understood. C. Bozzi - Status of Dilepton Mixing Analysis

  2. Systematic uncertainties (3) • Time-dependence of the mistag: • reminder: we absorb the time distribution of cascade background with a time-dependent mistag • “slope” for same-sign events • “slope”+”bump” for opposite-sign events • systematic uncertainty on Dm: difference with perfect-tagging complete fit: 2.5% (a conservative approach) • estimate with MonteCarlo is under way • might be better if cascade background is reduced. Cut tighter on NN output ? • We have to find a tradeoff C. Bozzi - Status of Dilepton Mixing Analysis

  3. Systematic uncertainties (5) • Knowledge of the resolution function: • apply the same cuts of the analysis on inclusive J/y in data and MC • data/MC agreement is good. Uncertainties: 5% on narrow gaussian width, 10% on wide gaussian width, 10% on fraction • width of wide gaussian gives 1.6% on Dm, the others give about 0.5%. • Can be reduced by improving the resolution function using the event-by-event error C. Bozzi - Status of Dilepton Mixing Analysis

  4. Summary of systematic uncertainties Source of systematic error Relative error on Dm (%) Non-BBbar Background Not measured yet Lepton Mis-ID Not measured yet Charge asymmetry (e+ e-) negligible Mistag asymmetry (h+h-) negligible Correction for h(B0) h(B+) negligible Time-dependence of the mistag 2.5 Correction of the boost approximation 0.3 y-motion of the beam spot (<20mm) negligible Resolution Function (5% on s1) 0.3 Resolution Function (10% on s2) 1.6 Resolution Function (10% on fraction) 0.6 Tails of the resolution function In progress Time-dependence of the resolution func. In progress Sensitivity to G+ (PDG 98  1s) 1.5 Sensitivity to G0 (PDG 98  1s) 1.0 Total C. Bozzi - Status of Dilepton Mixing Analysis

More Related