Data Taking and Related Works for R Scan above 3.8 GeV

Guangshun HuangUniversity of Science and Technology of China

Group Meeting

R scan 2

R Scan Strategy (Big Picture)

• 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 2.03.6 GeV, step 100 MeV, 100k+ hadrons<3 GeV.•Phase III: scan resonance region, 2 months 100 points in 3.84.6 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?)

6%

3.5%

Y(2175)?

Charm baryons

to extend?

Babar

R scan 3

Desired Energy Points in 3.854.6 GeV

• R measured by BESII (63)• R interpolated (42)

105 in total

R scan 4

Expected Instantaneous Luminosity and Data Taking Time for 100k Hadrons

L(Ebeam) E∝ beam-10 (Ebeam>1890 MeV)

R scan 5

Energy Points in 3.854.6 GeV (1)105-point fine scan, 100k events each point, assuming that L(Ebeam) E∝ beam

-10, Lmax = 0.65×1033 cm-2s-1 at 1.89 GeV

R scan 6

Energy Points in 3.854.6 GeV (2)105-point fine scan, 100k events each point, assuming that L(Ebeam) E∝ beam

-10, Lmax = 0.65×1033 cm-2s-1 at 1.89 GeV

60 days

11 hr*

10 hr*

* Scale recent 4260 and 4360 data taking

R scan 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:– 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 • 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)#

onlin

e ha

dron

s

Ecm or point

Lact

ual/L

plan

Ecm or point

Ecm or pointDate

R scan 15

Summary Tables (examples here)Overall:

Ecm(GeV)

Nhad (expected)

Lum. actual (plan)

(1/pb, online)

Testimated(hour)

Tactual(Tpure)(hour)

3.4 20000 1.6583(1.4935) 8.4+4 10(4.8)3.4 Separated beam 4 5.3(4.0)

2.8 50000 3.0993(3.0680) 28+8 37(17.5)

2.4 50000 2.3409(2.3329) 34+12 94(35.4)2.4 Separated beam 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!

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