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

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

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

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

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

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

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

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

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

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

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

Webpage R scan

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

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

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

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

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

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

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?

BaBar measurements using ISR