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NA60 weekly meetings. First look at the pA@158GeV 2004 data, burst by burst. Pedro Martins CERN, 2/3/05. Data used. All the files reconstructed by Ruben stored on na60tera2. 152 runs, totalizing 8781 bursts. If 1 burst = ~20 seconds, then 8781 are 175620s=48.7 hours!
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NA60 weekly meetings First look at the pA@158GeV 2004 data, burst by burst Pedro Martins CERN, 2/3/05
Data used • All the files reconstructed by Ruben stored on na60tera2. • 152 runs, totalizing 8781 bursts. If 1 burst = ~20 seconds, then 8781 are 175620s=48.7 hours! Therefore, the whole 158 GeV preproduction corresponds to aproximately 2 days of continuous, non-stoping, utopic data taking (who was on shift?)...
Data pre-selection Region B ~50% The area selected corresponds to ~80% of the events Region A ~25%
Region A: - Run 11360 to 11400 - 2477/8781=28% of the total bursts. Region B: - Run 11430 to 11560 - 4192/8781= 48% of the total bursts.
Approximate value of our lifetime At first look, and without any fits our lifetime is around 95%. Regions A + B are the ones were we see that the lifetime was more stable for a bigger period. A B
Lifetime and beam intensity The average beam intensity is different in regions A and B, however the lifetime is similar. 1 2 Intriguing: In region 1, the beam increases by a factor of almost 2 above the average, where the lifetime drops (still > 90%). In region 2, when the beam increases by ~15%, the lifetime drops again, but to approximately the same value shown in 1! B A
Check of the muon and muon reconstruction rate Remarks: • Through every burst, the number of dimuon triggers was stored as well as the number of reconstructed dimuons and single muons. However, this plots don't take into account that the muons reconstructed (at the PC level) could have nothing to do with the muons detected by the hodoscopes. • The “P1P2 trigger” flag can also appear simultaneously with the “dimuon trigger”. Unfortunatelly, this was not taken into account. The rate of P1P2 triggers should not affect so much the plots for the 158 GeV as it does for the 400 GeV.
Dimuon reconstruction rate through time As expected, when the beam intensity decreases, the dimuon reconstruction rate increases. Since this reconstruction is only at the PC level, I presume that this behaviour is strongly correlated with the occupancy in the muon chambers.
Putting some things together... In 46% of the dimuon triggers, we are able to reconstruct, at least, a single muon track. This rate doesn't seem to be affected by the beam intensity, which basically means that the u ratio gives an offset to the uu ratio. Warning: at this level, there's no way to check if the reconstructed muons were the muons triggered or not. Also, some of the dimuon triggers could be “P1P2”...
Conclusions (peeking on the next episode) • My main objective was accomplished: to learn how to open our files and how to “play” with the values that are stored. • All argos are in agreement, albeit only argonia 1 is shown. Argonia 3 differs from 1 and 2 by a factor of 10 times less counts. • The factor used to get the “real” proton intensity on the target from the argos was the “famous” 6600 (66000 for Argo 3). • All the plots presented don't depend on our magnetic (ACM, PT7) configuration. The only notorious fact is that we get less triggers per burst when we use have a negative ACM. • Repeat the macro, storing all the trigger flags. This should solve the problem of P1P2 triggers counted as uu. • 400 GeV: use the same procedure. • Creation of a “good run list” based on the argonias measurements.