1 / 25

      

      . (Episodio II). Signal/Background. X-section  [  b]: 2.04  10 -3 9.87  10 -3 0.30  10 -3 0. 46 0.14  10 -3. Reaction:             0  e  e        0 e  e   0. Most frequent charged  decays :

myron
Download Presentation

      

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.   (Episodio II)

  2. Signal/Background X-section  [b]: 2.04  10-3 9.87  10-3 0.30  10-3 0. 46 0.14  10-3 Reaction:    0  ee 0 ee0 • Most frequent charged  decays: • BR() = (22.73±0.28)  10-2 • BR(0) = (4.60±0.16)  10-2 • BR(ee) = (6.8±0. 8)  10-3

  3. Analysis versus EVCL Stream correlation for MC charged RAD investigated: run RAD, RPI & RAD, KPM & RAD & RPI ALL RAD RPI KPM

  4. SelectionCriteria(seeMarek J. talk) • EventSignature: • 2 PNC: |tcl-lcl/c|<5st • Recoilphoton: mostenergetic cluster withEg250 MeV • 2 tracksclosestto IP (using PCA, no vertexrequirement) • KinematicalConstraints: • Two body fdecaykinematicstocalculateEgrecoil • hkinematicstocalculategh • gh: |Et-Pt|<10 MeV (EtPt) • Best Photon: wechooseone PNC withq<0.2 radto the calculatedgh(OPAN) Main background is0 (B:S=200:1): M(gfgh) Mp0 • Background hypothesys: • in the 0 rest frame cosqgfgh>-0.98 • in the planeq gfghversus Eghgood S/B separation

  5. Background rejection Main background is 0 (B:S=200:1): M(gf gh) Mp0 • Background hypothesys: • in the 0 rest frame cosq gf gh >-0.98 • in the plane q gf gh versus Egh good S/B separation Signal Bkg q gf gh q gf gh q gf gh Signal Bkg Egh(MeV) cosq gf gh (psys) Egh(MeV) Egh(MeV)

  6. RAD&RPI gh : BestPhoton Black: Pre-Selected Blue: EtPt +OPAN Green: (PI0) cosq gf gh >-0.98 Red: (Inside) plane q gf gh versus Egh MeV RAD RPI MeV MeV

  7. gh : BestPhoton, PI0 Black: cosq gf gh (RAD & RPI)/Selected(RAD & RPI) Red: cosq gf gh (RAD)/Selected(RAD&RPI) Blue: cosq gf gh (RPI)/Selected(RAD&RPI) e MeV

  8. gh : BestPhoton, Inside Black: Inside Cut (RAD & RPI)/ cosq gf gh (RAD & RPI) Red: Inside Cut (RAD)/cosq gf gh (RAD&RPI) Blue: Inside Cut(RPI)/ cosq gf gh (RAD&RPI) e MeV

  9. pph.M() Black: Pre-Selected Blue: EtPt +OPAN Green: (PI0) cosq gf gh >-0.98 Red: (Inside) plane q gf gh versus Egh RAD RPI Mpp (MeV) Mpp (MeV)

  10. Cosqhp(ppsys) Black: Pre-Selected Blue: EtPt +OPAN Green: (PI0) cosq gf gh >-0.98 Red: (Inside) plane q gf gh versus Egh RPI RAD Cosqhp Cosqhp

  11.   L(run 2005) = 130pb-1 N(h) 105 Efficiency study: going on…

  12.  

  13. Signal/Background Reaction:     ()    0  ee 0 ee0 X-section  [b]: 6.04  10-5 8.80  10-5 2.04  10-3 9.87  10-3 0.30  10-3 0. 46 0.14  10-3

  14. SelectionCriteria • EventSignature: • 2 PNC: |tcl-lcl/c|<5st • Recoilphoton: lessenergetic cluster withEg>20 MeV (89%) • 2 tracksclosestto IP (using PCA, no vertexrequirement) • KinematicalConstraints or KinematicFit ?: • Two body fdecaykinematicstocalculateEgrecoil • Best Photon: wechooseone PNC withq<0.2 radto the calculatedgh • ……..

  15. MC Simulation • V00: official MC only with r-contribution • V01: PMCC using the matrix element as from Gormley et al. [PRD2(1970)] • V02: PMCC Pure phase space V00 Egh(MeV)

  16. Comparisonwithh Background investigation: from  we learn how to reject 0 ; Stream versus two photon invariant mass V00 Mgg (MeV)

  17. Egf and Egh After Pre-Selection Egf (MeV) Egh (MeV)

  18. Outlooks… • Work on selection efficiency is going on • Data-MC looks promising Preliminary investigation on  • Selection to be optimize • Improve MC Simulation? QCD AnomalyP p+p-g unitary effects via final state interactions: • WZW in the context of HLS • Chiral unitarity approach Bethe-Salpeter-equation • Omnes function

  19. SPARE

  20. h kinematics to calculate gh From 2-body fdecay  Eg recoil: From hdecay we disentangle our control sample: 0

  21. Control Sample: 0

  22. PhysicsMotivations Gormley et al. Phys. Rev. D2 (1970) 501 Angular distribution expected QCD Anomalyh/h p+p-g unitary effects via final state interactions: • WZW in the context of HLS • Chiral unitarity approach Bethe-Salpeter-equation • Omnes function

  23. PastResults: +- 1970-BNL:Gormley et. Al Phys. Rev. D2, 501 (1970) 7250 events spectra agree with simple r-dominant model 1973:Layter et. al Phys. Rev. D7, 2565 (1973) 18150 events spectra agree with r-dominance of the+- final state Gormley Layter

  24. PastResults: +- 1975: A.Grigorian et. al Nucl. Phys. B91, 232 (1975) 474 events 1984-TASSO: 130 events 1987-ARGUS: 795 (1990: 2626) events 1987-TPC-: 321 events 1984-PLUTO:195 events 1990-CELLO:586 events 1992-WA76: 401 events 1991-Serpukhov: 2491 events 1997-Crystal Barrel: 7392 events Box Anomaly evidence (independent of any assumption on r) 1998-L3: 2123 events well described by resonant contribution (published spectra no background subtracted) CB

  25. Conclusions and Outlooks KLOEKLOE2: unique opportunity to search for Box Anomaly •  : analysis with full KLOE data set, good results from background suppression and promising MC-Data comparison •  : very very preliminary work on MonteCarlo (toy!), insert element matrix in GEANFI; analysis with KLOE2 data set • KLOE2 data set ….

More Related