1. Data Taking and Related Works for R Scan above 3.8 GeV
Guangshun Huang
University of Science and Technology of China
Group Meeting

2. R Scan Strategy (Big Picture)
Charm
baryons 6%
3.5%
Y(2175)?
Babar
Phase I: pre-study, 7 days
Machine study at 2.0, 2.5 and 4.2(4.6) GeV, MC tuning, …
Phase II: scan continuum region, 100 days
15 points in 2.03.6 GeV, step 100 MeV, 100k+ hadrons<3 GeV.
Phase III: scan resonance region, 2 months
100 points in 3.84.6 GeV, 100k events, step 2, 5,10, 20 MeV.
Single/separated beam for beam associated background study.
(108 hadrons at 4040, 4160, 4415 for radiative decay search?)
to extend?
R scan

3. Desired Energy Points in 3.854.6 GeV
105 in total
R measured by BESII (63)
R interpolated (42)
R scan

4. Expected Instantaneous Luminosity and Data Taking Time for 100k Hadrons
L(Ebeam) ∝ Ebeam-10 (Ebeam>1890 MeV)
R scan

5. Energy Points in 3.854.6 GeV (1) 105-point fine scan, 100k events each point, assuming that L(Ebeam) ∝Ebeam-10, Lmax = 0.65×1033 cm-2s-1 at 1.89 GeV
R scan

6. Energy Points in 3.854.6 GeV (2) 105-point fine scan, 100k events each point, assuming that L(Ebeam) ∝Ebeam-10, Lmax = 0.65×1033 cm-2s-1 at 1.89 GeV
10 hr*
11 hr*
* Scale recent 4260 and 4360 data taking
R scan
60 days

7. More Realistic: from XYZ data taking
From Weimin Song:
R scan

8. More Realistic: from XYZ data taking
1.035
0.78 pb-1/hr
R scan

9. More Realistic: from XYZ data taking
The plan: 105 energy points, 100k events  integrated luminosity 4.9  8.4 pb-1 each point, average 6.6 pb-1, total 695 pb-1;
To simplify the experiment,  8 pb-1 will be taken at each energy (20% up on average);
Assuming the same rate of data accumulation, we need 8/0.78  10.3 hrs at each point, and total 8*105/0.78/24  45 days;
Assuming 1 hr beam tuning time at each point, we need 105 hrs  4.4  5 days;
J/, ’ fast scan for energy calibration, 6 times, 4 hrs each time, total 1 day;
Separated beam data taking, 2 points for 12 hrs, 1 point for 2 days, total 3 days;
Sum of above is 54 days. Remaining 6 days are reserved for trigger/BEMS study, maintenance, unexpected events;
In practice, 1 point per 12-hr BEPCII shift, 105 points = 52.5 days, but to be adjusted subject to actual situation.
R scan

10. Shift Weekly chiefs from USTC: Record keeping: Shifters:
Wenbiao, Haiping, Guangshun.
Record keeping:
One student per week, possibly with help from other institutions.
Shifters:
All of us. Highest priority during data taking!
R scan

11. Energy Calibration
Fit of J/, ’ fast scan: Bingxin
R scan

12. Webpage
R scan

13. Progress Plot “地铁运行图” Initially all points grey out;
Points become solid after data taking;
Current point blinking.
“地铁运行图”
R scan

14. Other Plots (illustrative only here)
Date
Ecm or point
# online hadrons
Ecm or point
Lactual/Lplan
Ecm or point
R scan

15. Summary Tables (examples here)
Overall:
Ecm
(GeV)
Nhad (expected)
Lum. actual (plan)
(1/pb, online)
Testimated
(hour)
Tactual(Tpure)
3.4
20000
1.6583(1.4935)
8.4+4
10(4.8)
Separated beam 4
5.3(4.0)
2.8
50000
3.0993(3.0680)
28+8
37(17.5)
2.4
2.3409(2.3329)
34+12
94(35.4)
6.5(4.1)
2.23
35000
1.4657(1.5000)
42+12
45.6(27.9)
Each point:
R scan

16. Data Quality Check
Preparation should start immediately: auto-mated scripts to generate plots;
Similar to Liang Yan’s work for 2012 scan.
R scan

17. TOF Calibration
Shengsen needs helper, ideally based at IHEP. Training should start soon.
R scan

18. Summary We are going to take data soon;
Please pay full attention – get ready for it!
R scan

19. LundArlw tuning Must introduce auto-tuning mechanism:
tuning with the Professor package;
tuning with Ronggang's grid method: list of parameters; lot of MCs need to be generated in advance;
to include known cross sections/branching fractions in MC, just let LundArlw handle unaccounted parts?

20. BaBar measurements using ISR