Dear Powel, Thank you for the information. For the tracking efficiency calculations, how many planes were allowed to be missed (in X-Y and U-V) for a track in a module? I assume they were not calculated by inserting MC tracks into real data. What were the reference tracks compared to for the calculations? How do ghost tracks play in the efficiency calculations? The tracking efficiency for T3 at 12 degree for central events (trigger6 ~ 28% central), which you said 70%, is much better than I've guessed. If it's the case, do you think we can use T3 as we initially planed to use for at 12 degree, i.e. reconstructing tracks in T3 instead of relying on external tracks to find hit association? Is the low efficiency for T5 mainly due to background or using 2 modules? Too many questions. I'll stop here. JH ----- Original Message ----- From: Pawel Staszel To: brahms-l@bnl.gov Sent: Wednesday, November 14, 2001 1:35 PM Subject: Re: DC and Run Plan (Re: Run plan) Dear J.H. Lee The centrality dependence analysis for DCs has yet not been done so I can not answer most of your question right now. The track reconstruction efficiencies for the latest runs at 12 deg. for DCs are T3: 70% T4:92% and T5: 70% (only 2 modules for T5 are used). Is is for the trigger #6 events. The efficiencies per plane in T4 and T5 are about 90%. This value is not corrected for a dead channels. Lets us continue this discussion tomorrow. Pawel. "J.H. Lee" wrote: ----- Original Message ----- From: "Zbigniew Majka" <ufmajka@cyf-kr.edu.pl> To: <brahms-l@bnl.gov> Sent: Tuesday, November 13, 2001 12:47 PM Subject: Run plan > .... > Justification: > 1. All DCs are working and we have to try to use them > to obtain unique results. > .... > Zbigniew > Dear Zbigniew and Powel, It would be very nice if you could add some more information on "all DC's are working" for the people who are not so familiar with the details of DC performances to help decide what program we would focus on for the rest of the run. I understand that still a lot of work is required to answer some of the questions, but I think it would be very informative for all of us if you let us know as much as possible on those questions. Thank you in advance. 1. Efficiency - What are the plane-by-plane efficiencies (hardware efficiency) with the current HV and threshold settings? I assume the numbers are quite high (>90%?), otherwise we'll have serious difficulties to reconstruct tracks. - What are the centrality dependent track reconstruction efficiencies (software efficiency, if you like)? I understand those numbers are much harder to estimate, but we have to know them for any yield calculations as we all know. One of the ways to estimate the numbers is inserting MC tracks into real events or merging two reconstructed events and try to reconstruct the mixed events. 2. Track Reconstruction at 12 (and 20 and 3/4) degree - What are the mean number of the hits in the planes as a function of the centrality (Tile ADC Sum, BB Multiplicity, or Trigger 6)? - If you reconstruct tracks with the current CD configurations and reconstruction software/geometry/parameters, what are the mean numbers of tracks in T3, T4, and T5 as a function of the centrality? - What are the numbers for (T4+T5 matched tracks)/(T4 tracks) or (T4+T5 matched tracks)/(T5 tracks), also as a function of the centrality? 3. Extrapolating Tracks - How does a distribution of "position of T2 tracks projected on T3 - position of the nearest hit in T3", say for central (or trigger6) events at 12 (and 20, 3/4) degree? This will more or less tell us whether we can utilize T3 without recontructing tracks in it. Regards, JH -- ---------------------------------------------------------------------- | Pawel Staszel | | Niels Bohr Institute Tb 8 email: staszel@nbi.dk | | Blegdamsvej 17 phone: (+45) 35 32 53 51 | | København Ø FAX: (+45) 35 32 50 16 | | Danmark | ----------------------------------------------------------------------
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