1. Gluon Gluon to jpsi jpsi
Wang Jian

2. Typical Feynman diagrams of pair production in p p collision at leading order in color-singlet scheme

3. Typical Feynman diagrams of pair production in p p collision at leading order in color-singlet scheme
The generator is on the basis of FDC system(arXiv: hep-ph/ )

4. Theoretical calculations in Mathematica Generator results
Comparison between theoretical cross-section calculations and the results of my generator (see arxiv v3 for mathematica results)
Down limit
(2jpsi)
( )
Theoretical calculations in Mathematica
Generator results
Single-color
Octet-color
5GeV
1.08pb
1.15pb
1.329pb
1.492pb
6GeV
0.37pb
0.74pb
0.402pb
0.908pb
7GeV
0.14pb
0.49pb
0.144pb
0.583pb

5. Possible reason for the difference
PDF in mathematica calculation is CTEQ5,but that in Generator is CTEQ6.
If set the down limit of Pt of double jpsi at 10GeV，
Cross-section of single-color model is pb
Cross-section of octet-color model is 0.197pb

6. Selection criteria Four muon For each muon, Pt>3GeV, |eta|<2.2
First dimoun with different charge to form a jpsi, mass window is 0.18GeV
Second dimoun with different charge to form a jpsi, mass window is 0.18GeV
Four muon vertex fitting, CL>0.001

7. Description
Color-single signals
Color-octet signals
Number of events
Efficiency
Generated events
20 (responding to 1.274/fb)
100%
1000 (responding to 5.076/fb)
L1 trigger
HLT
Four muons are reconstructed 2
136
13.6%
For each muon of first dimuon, Pt>3GeV, |eta|<2.2
Mass window of first dimuon
132
13.2%
For each muon of second dimuon, Pt>3GeV, |eta|<2.2 1 71
7.1%
Mass window of second dimuon 68
6.8%
Vertex fitting (CL>0.001)

8. Number of general tracks

9. Octet-color model: between MCmuon and MCjpsi

10. For events that only 3 muons were reconstructed，the unreconstructed muon could be searched in cone that dr<1 from residual reconstructed muon.
Primary backgrounds：
prompt Jpsi

11. In more than 1.84 million prompt jpsi events, none was left after selection according to the above cretirias.