1 / 10

p + p - Transitions to Charmonium States above open charm threshold

p + p - Transitions to Charmonium States above open charm threshold. BaBar Discovery. e + e -  g(p + p - J/ Ψ ) (E cm ~10 GeV). Y (4260). Too narrow to be regular charmonium state?. CLEO Confirmation. Phys.Rev.Lett. 96 (2006) 162003. We now have a large data set at 4.17 GeV (Ds data)

ave
Download Presentation

p + p - Transitions to Charmonium States above open charm threshold

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. p+p- Transitions to Charmonium Statesabove open charm threshold

  2. BaBar Discovery • e+e-g(p+p-J/Ψ) (Ecm~10 GeV) Y(4260) Too narrow to be regular charmonium state?

  3. CLEO Confirmation • Phys.Rev.Lett. 96 (2006) 162003 We now have a large data set at 4.17 GeV (Ds data) ~ 12 times more data at this energy than before I have analyzed it to verify our previous results for p+p- J/Ψand to look for p+p-J/Ψ

  4. Electron 0.05 <P<2.0 Hit fraction >0.5 D0 <0.005 Z0 <0.05 dE/dx: esigma > 2.5 0.8< E/P <1.1 Muon 0.05 <P<2.0 Hit fraction >0.5 D0 <0.005 Z0 <0.05 dE/dx: musigma > 2.5 0.15< E< 0.45 Cuts applied e+e-p+p- J/, J/e+e- or μ+μ- • Pion • 0.05 <P<2.0 • Hit fraction>0.5 • D0 <0.005 • Z0 <0.05 • dE/dx: pisigma > 2.5

  5. After the cut: | Ml+l-- MJ/Ψ|<0.05 GeV e+e-g ′ ′p+p- J/ e+e-p+p- J/ , e+e-g ′ ′p+p- J/  M(p+p-J/y) To further reduce the backgrounds we cut: |Pπ+π-l+l- x,y,z | < 0.1GeV , |Eπ+π-l+l- - 2Eb| < 0.2GeV, and extract the number of events in the 2nd peak by fitting Ml+l- (with the cut on Ml+l-removed).

  6. MC (20000 events): e+e-p+p- J/, J/e+e- & μ+μ- Ml+l-

  7. Data(Ds*Ds):e+e-p+p-J/, J/e+e- & μ+μ- Ml+l-

  8. σ(e+e-p+p- J/) • ε= 0.531 ±0.005 • L = 315 pb-1 ±2.4 • Nfit = 197 ±21 • Subtract psi’ tail by assuming the same psi’ fraction as in the published paper (not quite correct): • 197  141 signal events • σ (p+p- l+l-)= N/(εL) =0.84 ± 0.09 • σ (p+p-J/)= σ (p+p- l+l-)/BR( J/l+l-) • BR( J/l+l-)= [BR( J/e+e-)+ BR( J/μ+μ-)]/2 = 0.06 ± 0.0004 • σ (p+p-J/)=14 ± 1.5 pb

  9. My result Consistent with the published results!

  10. p+p-' p+p-J/, J/e+e- or μ+μ- M(J/y) M(p+p-J/y) Cuts: |E π+π-π+π-l+l- - 2Eb| < 0.2GeV, |P π+π-π+π-l+l- x,y,z| < 0.1GeV

More Related