Data Taking and R elated Works for R Scan above 3.8 GeV

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, 100kevents, 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 • R measured by BESII (63) • R interpolated (42) 105 in total 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= 0.65×1033cm-2s-1at 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= 0.65×1033cm-2s-1at 1.89 GeV 60 days 10 hr* 11 hr* R scan * Scale recent 4260 and 4360 data taking

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-1will 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: • 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. R scan

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

Summary Tables (examples here) Overall: 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

Data Taking and R elated Works for R Scan above 3.8 GeV