1 / 12

First steps to radiative return studies at Belle

First steps to radiative return studies at Belle. B.A.Shwartz BINP, Novosibirsk. Plan. This is our first steps to see what can be done at Belle for radiative return physics. The events with 2 charged particles were studied. Basic things A sample for first study

lynley
Download Presentation

First steps to radiative return studies at Belle

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. First steps to radiative return studies at Belle B.A.Shwartz BINP, Novosibirsk TAU-04, NARA

  2. Plan This is our first steps to see what can be done at Belle for radiative return physics. The events with 2 charged particles were studied • Basic things • A sample for first study • What’s seen for: gmm, gpp, gKK and gp pp0 TAU-04, NARA

  3. e+e   0 1 30 TAU-04, NARA

  4. Comparison to VEPP-2000 project, ee up to 2 GeV (under construction at BINP) TAU-04, NARA

  5. A sample to study • The Tau-pair sample (skim) is used ( 2<Ntrk<8, Pch<9GeV, Eecl<9GeV) • Then the following cuts were applied: • Ntrk=2 • 10<Erec<11　GeV • Ptot <0.5 GeV • Ng>0 • Egmax>3 GeV • 0.7<<2.6 • Pmin >0.7 GeV (charged) 25.9 fb-1 is used study TAU-04, NARA

  6. Ptot Pg Erec Minv Eg2<0.2 (for 2 particles modes) TAU-04, NARA

  7. Two particle events All events  , (p1m/p, p2m/p >0.5) Minv(2tr), GeV Minv(2tr), GeV TAU-04, NARA

  8.   calculation   background TAU-04, NARA

  9. Npp/Nmm ratio By a simple separation procedure the number of pp and mm events are obtained and ratio is calculated (just demonstration, not for usage!) The difference 5% can be caused by the different trigger efficiency for pion and muon events. This is a measure of systematics. TAU-04, NARA

  10. How to compare with BaBar? N=183093 M =31061 MeV =16.30.9 MeV 71 J/ per 1 fb-1 From BaBar J/  paper – 7800 J/  event at 88.4 fb-1  88.2 J/  per 1 fb-1 TAU-04, NARA

  11. 0 KK ECM – (｜pgmax ｜+｜p+ ｜+p ｜)>1 GeV TAU-04, NARA

  12. Conclusion • Events with radiative return can be seen at Belle with reasonable efficiency. • New Bhabha trigger implementation should improve the trigger efficiency at low invariant mass area TAU-04, NARA

More Related