1 / 28

Beyond SM Physics at a CLEO Charm Factory (some food for thought) Mats Selen, UIUC, May/5/2001

Beyond SM Physics at a CLEO Charm Factory (some food for thought) Mats Selen, UIUC, May/5/2001. Data Assumptions Tagging Rare decays D mixing CP violation Off The Wall. Data Assumptions. Assume we will accumulate 3 fb -1 on the ”(3770) 10 nb signal, 12 nb “other hadronic”:

luke-owen
Download Presentation

Beyond SM Physics at a CLEO Charm Factory (some food for thought) Mats Selen, UIUC, May/5/2001

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. Beyond SM Physics at a CLEO Charm Factory(some food for thought)Mats Selen, UIUC, May/5/2001 • Data Assumptions • Tagging • Rare decays • D mixing • CP violation • Off The Wall

  2. Data Assumptions • Assume we will accumulate 3 fb-1 on the ”(3770) • 10 nb signal, 12 nb “other hadronic”: • About 3x107 DD pairs • Assume BaBar & Belle will (each) have 400 fb-1 on the (4S) • 1.3 nb signal, 3 nb “other hadronic” • About 5x108 cc pairs each • Our competition will have ~17 times more charm on ~33 times more “other hadronic” background.

  3. Big Advantage: Tagging: • Two important benefits: • Flavor ID • Unambiguous Reconstruction e- • Suppose efficiency x BR (all tags) = 10% (more on this..) • Will have ~ 106 each tagged D0 and D+ per 1 fb-1 • Limits of order 10-6 possible from 3 fb-1 data (still pretty good) e+ e- e+ p- K+

  4. p0 e- e+ e- e+ p- K+ Rare Decays Example Study: D0 p0e+e- • In 32290 generic D0 decays: • 1098 D0 K-p+tags (eB=3.4%) • 1543 D0 K-p+ p0tags (eB=4.8%) (DC=1 Weak Neutral Current) Tag using: D0 K-p+ (B = 3.83%) D0 K-p+p0 (B = 13.9%) With just these two modes, eBtag=8.2% Working Group: What is the tradeoff: efficiency vs cleanliness

  5. …if we don’t properly exclude tagged tracks Ability to get rid of this stuff is a keyadvantage! Tagged events epeexeBtag= 1.5% Notag ~ 500 evt

  6. Suppose epee.eBtag= 1.5 % Suppose we have 3 fb-1 (~1.5x107 D0D0 pairs) Suppose we see 0 events 90% CL upper limit is ~5 x 10-6 About a factor of 100 improvement over PDG in most cases. Most modes studied were in the 10-6 10-5 range Its hard to imagine BaBar/Belle would not be in the same ballpark,although based on simple scaling I think we have the edge inclean modes where they are background limited. See Excel Table See Bruce Yabsley’s talk in beyond SM working group

  7. For example… CLEO-c B-fact Simple spreadsheetanalysis tool available for working group.

  8. CLEO-II Presently:90% CL Upper Limits < 2.4x10-4 For both modes CLEO-II wg rg Some interesting examples: • 1) B(D0 gg)- SM small: ~10-8 (Singer et. al. hep-ph/0104236) • - good hunting for physics beyond SM. • - no present limit, CLEO-c sensitivity ~ 10-6 • 2) G(D0 rg) / G(D0 wg)(Fajfer et. al. hep-ph/0006054) • - Individual BR’s small: ~10-6 • Long distance effects cancel in ratio. • - Ratio should be ~1 (30% deviation means new physics) See Will Johns’talk in beyond SM working group

  9. In hadronic decays: K- D0 D0 D0 D0 MIX K+ y = DG/2G (real) D0 DCS CF K-p+ W W D0 x = DM/G (virtual) d = dR–dW (important to measure) r = A /A Mixing Phenomenology:

  10. D0-D0 Mixing: At the Y(4S) Con • Ultimately limited by Backgrounds & Systematics CLEO K*ln analysis CLEO K3p analysis Pro • Lots of data • Time evolution handle

  11. 0.1 y 0 -0.1 0 0.2 0.1 x Experimental Situation (May/2001)

  12. D0-D0 Mixing: At the ”(3770) Pro • Tagging ! • - Flavor known • - All tracks accounted for • Quantum Correlations - opens up new avenues of search: K+ p- e- e+ p- K+ Con • No Time evolution handle: D0’s produced ~at rest • Can’t measure DG directly using lifetime differences.

  13. The D0 and D0 are produced coherently in a JPC = 1-- state. • Time integrated decay rate to final state f1,f2: K+ p- e- e+ (assumes CP conserved) p- K+ See hep-ph/0103110Gronau, Grossman & Rosner (and also working group tomorrow) Looks slightlydifferent for C +initial states likeDDg

  14. K- K- p+ p+ p+ p- K- K+ Useful for probing x & y Ratio of Rates: Interesting Case 1:

  15. KS K+ K+ KS r0 K- r0 K- p- p- p- p- CP- eigenstate CP- eigenstate K+ K+ K+ K+ = 2 r cosd Useful for probing r & d CP+ eigenstate Asymmetry = Interesting Case 2: CP+ eigenstate There are several other interesting cases to study: See Jon Rosner’s & Alexey Petrof’s talks in beyond SM working group

  16. u p+ d c s K0 D0 d K*- u u d p- CF: D0 K*-p+ Fit for these in Dalitzplot… Mix or DCS: D0 K*+p- Another Example:D0K0p+p-Dalitz Plot Analysis to extract mixing parameters: …along with other good stuff: other K*’s, K2, r, w, f0, f2…

  17. In CLEO II.V: Sensitivity to x & ywill be about 3% See “wrong sign”decays at 5s level. See David Asner’s talk in beyond SM working group

  18. u u D0 p-r+ D0 r-p+ p+ r+ d d c c d d p- r- D0 D0 u u u u D0 p0r0 p0 c c d s d u u u u u r0 Also accessible from the D0 Interference ! Yet another Example:D0p+p-p0Dalitz Plot Analysis: D0 K0p0 K0 d D0 D0 u p0

  19. MD*-MD r+ r- KS r0 CLEO-II.V D0p+p-p0Dalitz Plot Analysis (preliminary): At CLEO-c we will have 5-10x more events with no background

  20. D f Compare Df to Df D f Direct CP violation: Need two paths frominitial D to final state f.

  21. Find: Direct CP violation: Good News: We know large strong phase differences (d1- d2) are not uncommon in charm decays! This is an important ingredient. Good/Bad News: Expect small weak phase differences in Standard Model. SM ACP may be as big as 10-3for some decay modes Definitely a hunting ground for new physics.

  22. Observing this is evidence of CP CP(f1 f2) = CP(f1) CP(f2) (-1)l = CP- K+ + - (since l = 1) K- e- e+ p- p+ At the ”(3770) e+e- ”  D0D0 JPC = 1-- i.e. CP+ Suppose both D0’s decay to CP eigestates f1 and f2: These can NOT have the same CP :

  23. CP violation in Dalitz Plots: Example Search: D0 K-p+p0

  24. Fit D0 and D0 Dalitz Plots separately and look for asymmetries: D0 - D0 “Difference” Plot Find ACP= 0.0310.086 Better sensitivity to new physics expected in CS modes. Some are under investigation: D0 K-K+p0 and D0 p-p+p0 This will be easier to do at a charm factory than at Y(4S) due to backgrounds. See Daniele Pedrini’stalk in beyond SM working group Q: Are structural differences that integrate to zero interesting?

  25. General Observation High statistics background free DalitzPlot analyses will be a great place to lookfor interesting physics at CLEO-c Not only “Beyond SM”, also QCD etc..

  26. The size R of the extra dimension is given bywhere MP is the 4-dimensional Planck scale. Rn ~ MP2MS-(n+2) g photon q J/ Look for q h,f graviton or dilaton (undetected) If time, end with something just for fun:Sensitivity to Large Extra Dimensions: From Bijnens & Maul hep-ph/0006042 If there are n large extra dimensions the decay J/g + (h,f) may be sensitive to the compactification scale MS:

  27. If BR( J/g + (h,f) ) < 10-5 we can set these lower boundson MS (as a function of n). Predicted photon spectrum

  28. There is lots of interesting physics “Beyond the Standard Model” that will be explored with CLEO-c Find out more at tomorrows working group:

More Related