1. Update on inclusive search of structure decays into J/ at BaBar
Kai Yi, Dong Su
Supporting note #: 1718
Journal draft #: (booked)
BaBar Collaboration Meeting, Jun
1/13/2019
Kai Yi

2. Presentation history First private presentation on Jan-26-2007:
Claudia, Shuwei, Jim, Hassan, Dong and Kai
Second private presentation (discussion) on Mar :
Claudia, Philip, Walter, Antimo, Bob, Jim, Dong and Kai
AWG intenal review committee assigned:
Antimo Palano, Bob Cahn, Denis Bernard, Chris Hearty, Walter Toki
Third private presentation on May
Review Committee assigned on Jun :
Antimo Palano (Chair), Denis Bernard , David Aston.
Also thanks to Frank Porter for statistical advice.
1/13/2019
Kai Yi

3. Motivation
The charmonium puzzle—”anomalous” production of charmonium at CDF (M. Mangano, Moriond QCD, 1994 and reference therein)?
Besides color octet, also imply hybrid states (PLB 342, 369, 1995)?
The renewed interests on charmonium by recent observation of X(3872), Y(4260) with various interpretations.
Charmed hybrid prediction: mass varies from 3.9 to 5.3 GeV
quenched lattice QCD: 4.390.08(stat)0.20(sys)?(quench) for ground
exotic state 1-+. (PRD 56,7039,1997. Happens to be the most precise found so far)
F. Close proposed to search in B decays (PRD 57, 5653, 1998)
CLEO and BABAR searched in B decays: (PRL 84, 1393, 2000; PRL 91, , 2003), B signals observed, but no substructure.
Search in B decays can reduce background, but may be limited by B phase space and decay mechanism.
Since J/ and  are “very” clean and narrow due to excellent PID at BaBar, it is plausible to do a inclusive search and may increase sensitivity.
note: J/ and  can also point to other possibilities such as molecule, four-quark states.
1/13/2019
Kai Yi

4. Motivation What about hybrid candidates for light quarks (u,d)?
Light hybrid prediction (1-+): mass between 1.85 and 2.1 GeV
PRD, 64, (2001), hep-lat/
Two 1-+ candidates:
1(1400); 1(1600)’;
Problems with explanation as hybrid:
1. mass not match
2. flux-tube-model (two quark with a vibrating gluon between) predicts decays should be dominated by an s-wave and a p-wave meson; here are two s-wave mesons.
Let’s look at data.
1/13/2019
Kai Yi

5. Dataset and reconstruction
Run1-5, R18 dataset, ~380 fb-1.
Jpsitoll skim, compared to Allevents, no difference.
Plan to move to R22, and use run 6.
Reconstruction:
—We first reconstruct a J/, mass range: [2.9,3.2], vtxprob>0.1%
—We then add two opposite-charged kaons to form a vertex. Vtxprob>1%
—We also form a  vertex and then put the two vertices together.
—This allows us for a double check.
—Selectors: NNVeryLooseMuon, eBremRecoELoose
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Kai Yi

6. J/ and  mass peaks after vertexing
mee
mKK in J/ee sample
mKK in J/ sample
conversion
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Kai Yi

7. Remove conversion by minimum SVT
mKK in J/ee sample
mKK in J/ sample
conversion
is gone
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Kai Yi

8. Minimum p* requirement
in J/ sample
in J/ee sample
mKK
m
mee
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Kai Yi

9. Vetoes: veto on reconstructed signals+additional leptons
mJ/Ks
mJ/K
mJ/
m
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Kai Yi

10. Summaries of cuts
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Kai Yi

11. J/ correlation
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Kai Yi

12. J/ mass distribution after all cuts
in J/ sample
in J/ee sample
Looks smiling 
Looks shy 
Get to that later
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Kai Yi

13. Modified Nine tiles
in J/ sample
in J/ee sample
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Kai Yi

14. Modified Nine tiles in J/ sample in J/ee sample
nine tile background
nine tile background
background subtracted
statistics limited
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Kai Yi

15. B Bbar background from data
It was suggested to look at the z significance to find BBbar control sample
as shown above. We choose the events outside 3 sigma as the control
sample
in J/ sample
in J/ee sample
z between J/ and  vtx
B Bbar background
mJ/
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Kai Yi

16. B Bbar background from MC
in J/ sample
in J/ee sample
B Bbar background from MC
Both data and MC shows no sub-structures
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Kai Yi

17. Preparations
MC: use AfkQed, assume Object+X, where X contains multiple particles, private version exists.
We may have to determine significance using toy MC, code also exists.
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Kai Yi

18. Additional check
if we have 100 fb-1 Run 6 data
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Kai Yi

19. Additional check
It only reduce 4 events after we require L1+L3+BGFilter in  sample
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Kai Yi

20. Additional check
No substructures when we reconstruct D0K with the K from 
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Kai Yi

21. The issue … What about J/ee sample?
We need to understand at certain level, I know 
Trying without Brem correction.
Trying VeryLooseLH electron.
There is hope, need more time. …
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Kai Yi

22. Conclusion Thank you! Trying to understand ee sample.
“Blind” test in trk-fixup dataset, blind test in Run 6 data?
Look for some observables
Publish it if significance > 3.5 sigma
If confirmed by other experiments or more BaBar data, follow a angular analysis to determine quantum number (hep-ex/ ), Selina join to help?
Claim discovery and cheers. 
Thank you!
1/13/2019
Kai Yi