Trigger rate studying

Shiuan-Hal,Shiu

Introduction Because the DAQ data taking

rate only have 1000Hz, we must confirm the trigger rate will not higher then the DAQ limit.

From the right figure, we can see that the J/ψ dimuon production rate is 100 times then Drell-Yan dimuon.

I suppose the J/ψ here is the major background, if the total trigger rate(contain the dy and J/ψ dimuons from target and dump) is higher then 1000Hz we must give the J/ψ trigger a prescale factor.

J/ψ

Mass

Rate

Event rate per second

Target Dump

Drell-Yan 3.8432 99.9261

J/ψ 13.7703 325.242

Single muon

? ?

The proton beam structure is 5 sec spill of 1*1013 protons each minute, it means when the proton comes we will have 2*1012 protons in each seconds.

Right table shows the simulation results of event rate per second from the E906 fast MC.

From the right table we can see that the J/ψ rate may not be a problem of E906 daq, I think now the main problem is random single muon from pion decay. But, now we have no idea to estimate the rate. We need real beam to measure it.

Some estimate

Without any look up table logic we have already used 5493/20060 (27%)logic elements, and (512*9*8*3+4096=114688) 114688/294912(39%) memory and ½(50%) PLL each v1495.

From a simple muon track simulation in bend plane, we found there are almost 1400 track conditions will appear for a positive muon. It means 2800 track combinations need to deal in one v1495, and in worst case may cost about 9000 logic elements. V1495 now still have 14567 logic element, I think it is enough.

In fast MC, we can modify the input event number. In general, more input event will have more road combination number. But the FPGA resource is not unlimited, so we need to find a stable value.

Road combination number In the table below the DY-target means the

Drell-Yan from target and DY-dump means the Drell-Yan from dump. 99% means the 99% events was contained in the number of roads.

10 million events

Total road

99% 99.9% 99.99%

99.999%

DY-target

Yp 656 24 96 230 392

Yn 668 21 101 229 388

DY-dump

Yp 763 21 89 174 296

Yn 774 20 80 168 290

J/ψ-target

Yp 185 23 60 96 171

Yn 192 23 58 104 173

J/ψ-dump

Yp 192 22 52 93 174

Yn 192 20 50 90 170

Road combination number

50 million events

Total road

99% 99.9% 99.99% 99.999%

DY-target Yp 876 22 96 238 414

Yn 896 21 104 241 420

DY-dump Yp 1038 20 81 173 304

Yn 1029 20 86 177 302

J/ψ-target

Yp 343 23 59 93 245

Yn 345 23 58 93 237

J/ψ-dump Yp 346 21 52 87 217

Yn 333 20 49 84 220

Road combination number Compare to the FPGA estimate and the fast

MC result, I think I’ll trend to choose the road combination in 99.99%. 100 million events

Total road

99% 99.9% 99.99%

99.999%

DY-target

Yp 1016 23 97 240 411

Yn 1053 21 101 241 424

DY-dump

Yp 1221 21 83 174 309

Yn 1212 20 86 182 317

J/ψ-target

Yp 441 23 57 93 237

Yn 427 22 58 92 238

J/ψ-dump

Yp 441 21 49 87 216

Yn 437 20 53 83 225

99% roads mass distribution(DY from target)

yp ynmass mass

counts counts

99% roads mass * sigwt distribution(DY from target)

yp ynmass mass

rates rates

99% roads mass distribution(DY from dump)

yp ynmass mass

counts counts

99% roads mass * sigwt distribution(DY from dump)

yp ynmass mass

rates rates

backup

Mass distribution of positive Drell-yan muon from target (99%)

Mass distribution of positive Drell-yan muon from target (99%)

Mass distribution of positive Drell-yan muon from target (99%)

Ptx distribution of positive Drell-yan muon from target (99%)

Ptx distribution of positive Drell-yan muon from target (99%)

Ptx distribution of positive Drell-yan muon from target (99%)

Mass distribution of negitive Drell-yan muon from target (99%)

Mass distribution of negitive Drell-yan muon from target (99%)

Mass distribution of negitive Drell-yan muon from target (99%)

Ptx distribution of negitive Drell-yan muon from target (99%)

Ptx distribution of negitive Drell-yan muon from target (99%)

Ptx distribution of negitive Drell-yan muon from target (99%)

Mass distribution of positive Drell-yan muon from dump (99%)

Mass distribution of positive Drell-yan muon from dump (99%)

Mass distribution of positive Drell-yan muon from dump (99%)

Ptx distribution of positive Drell-yan muon from dump (99%)

Ptx distribution of positive Drell-yan muon from dump (99%)

Ptx distribution of positive Drell-yan muon from dump (99%)

Mass distribution of negitive Drell-yan muon from dump (99%)

Mass distribution of negitive Drell-yan muon from dump (99%)

Mass distribution of negitive Drell-yan muon from dump (99%)

Ptx distribution of negitive Drell-yan muon from dump (99%)

Ptx distribution of negitive Drell-yan muon from dump (99%)

Ptx distribution of negitive Drell-yan muon from dump (99%)