Hi Let me start with the most important : You should be carefuil if you use the dsts on /brahms/data07/data/dst that you only use dsts generated within the last 24 hours or so. I have tried to get MRS yields from the new data (Claus, Ian, Djamel). I have looked at 5% central +- 15 vtx Z trigger 6 data. All the analysis tools can be found in : brahms_app/pc_app/spectra/dndy and is REALLY easy to use. You basicly just need to copy the dsts you want to use to your homedir (or run on rcas) and you can use the acc maps I have made for some settings (located in an afs dir see code) and it is easy to generate new acc maps. I have put the best results I have got in the same dir under results. The results uses Eun-Joos correction functions and has a 10% overall correction from the TOFW. I also noticed a charge assymmetry in the matching step that I had to correct for (The ratio of status 5 to status 1 tracks was very different for positive and negative tracks) to get pion ratios close to unity. It was later discovered (today) that this was due to the fact that the global tracking did not pick up the correct offsets and should be fixed now, but it means that if you use th dsts you should check that the date is within the last 24 hours or so. It also means that my results has some fudge factor of 4-10% that is also much to simple since it does not has a p dependence. Since I am now going on vacation for 1 week I thought it would be good to present some results anyway since they should say a little bit about what the final results should be, it gives other people doing the same analysis something to compare with and it gives the non analysers a chance to make maybe some multihistfit procedure to extract a transverse flow and temperature which can then be easily used when the final results are there. When we now get the new dsts with the right matching offsets I think there are a few critical pieces missing in getting good mrs yields and temperatures. 1) Select all good runs to get high statistics. This sounds trivial, but there are really a lot of runs with bad calibrations, missng TPM2, etc. that easily screws up things if we are not careful. So a list of runs used would be good to have from all doing the analysis. 2) TPM1 efficiency. I have some small project going on, but anything would be great. 3) TOFW efficiency. Do we just use a number or a setting/slat/momentum dependent number ? 4) Low pt. We really treat low pt bad everywhere. When we match tracks to form global tracks, project to TOFW, project to vertex, we loose a lot of low pt tracks because their angle resolution is worse because of multiple scattering (This could even be mass dependent). We might be able to make a simple simulation to get an estimate for this or just to get a feeling of how rough we are. It is my gut feeling (and hope;) after looking at the data that the rest of the efficiencies/corrections are much less significant. I also did 2 smaller projects In brahms_app/pc_app/spectra/dndeta is the software for making high pt non identified spectra and it seemed to work well when I tested it for Claus. In brahms_app/pc_app/tpc/Tpm1Eff there is a very simple efficience estimator module based on an idea by Pawel. It should only be used for 0-field runs. The idea is to opropagate TPM2 tracks through D5 (require good swim status) and point them to the vertex and require that they hit close to the BB vertex. The code works but could possible use a TOFW matching step to make better tracklets and a way to parameterise the efficiency in some way. When tested on 5572 it gave around 10% efficiency for TPM1 trigger 6 (2 methods for confirming cut in dx,dy,dax,day and cylinder overlap (1cm) 0.1 both gave roughly this). Cheers Peter Best results : y = 0 (0-5%) ===== Y T pi+ : 243 +- 4 230 +- 3 pi- : 247 +- 5 228 +- 3 K+ : 46 +- 3 276 +- 9 K- : 42 +- 2 282 +- 10 p : 28 +- 2 352 +- 12 pbar : 20 +- 2 391 +- 17 Comment : Error on results are from chi2 fits with E option. We have maybe to agree on some way to do it ? E(this), LE, L ? The increase from the last email i wrote is mostly done to a 10% correction for the TOFW that I have argued for. y = 0 (5-15%) ===== Y T pi+ : 181 +- 4 232 +- 2 pi- : 180 +- 2 231 +- 2 K+ : 33 +- 1 275 +- 6 K- : 32 +- 1 279 +- 7 p : 21 +- 1 370 +- 11 pbar : 16 +- 1 360 +- 12 Phenix 0-5% ================= pi+ : 276 +- 3 pi- : 270 +- 3 K+ : 47 +- 2 K- : 41 +- 2 p : 29 +- 1 pbar : 20 +- 1 Comment to phenix data : 30% of the pi are extrapolated and at really low pt <20% so a lot has to do with the function you choose. Phenix 5-15% ================= pi+ : 216 +- 2 pi- : 200 +- 2 K+ : 35 +- 1 K- : 30 +- 1 p : 22 +- 1 pbar : 14 +- 1 BRAHMS y ~ 0.8 (0-5%) ===== pi+ : 230 +- 4 212 +- 3 pi- : 221 +- 4 220 +- 3 K+ : 38 +- 3 329 +- 16 K- : 38 +- 2 315 +- 18 p : 22 +- 1 407 +- 22 pbar : 17 +- 1 427 +- 31 Comment:Things are more tricky here and I could/should spend some more times on this. The different settings looks consistent to within 10% (most are better). -- :-) --------------------------- )-: Peter H L Christiansen @ NBI EMAIL : pchristi@nbi.dk OFFICE : Tb1@NBI (353 25269) HOME : Hjertensfrydsgade 3, st PHONE : 33330493(New)/ 40840492(mob.) :-D --------------------------- \-:
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