Hi Everybody. I hope the high yield problem is solved after exchanging some message with Claus. I realized that in his acceptance map generating program there are some fiducial cuts (on TPCs). After applied the same cuts on data, a little bit complicated, the yields is much lower than before. I will run through both settings for pp and dAu for different centralities tomorrow to see if everything (R_dA for pi and h) looks fine. Best regards, Zhongbao ------- On Sun, 28 Dec 2003, Ian Bearden wrote: > Hi Zhongbao, > A couple of quick comments/questions...in line below: > On 28/12-2003, at 21.07, yin.zhongbao@fi.uib.no wrote: > > > Hello, > > > > I hope everyone will be back to work tomorrow :) > > > > What I found that the yields of charged particles from dAu and pp at > > midrapidty are much higher than other experiments (PHENIX, PHOBOS and > > STAR). For min-bias of dAu, the yields ~20% systematically higher than > > PHENIX published, while our published data is lower than PHENIX > > especially > > in low pt region. For 0-30% central dAu collision the yields I got even > > higher than that PHOBOS publilshed spectra from 0-20% central events. > > The > > reason I guess might be due to: scaledown correction and acceptance > > correction. I would appreciate you if you could provide me some idea or > > suggestion. > Do you have some plots showing this? In particular, it would be > interesting to see a comparison of your dAu spectrum > compared to the published dAu spectrum. > > > > For scaledown correction, it is clear that the inel trigger scaledown > > factor is vertex position and centrality dependent from a > > two-dimensional > > histogram. I think it is quite understandable since the inel trigger > > efficiency has weak centrality and vertex position dependence. > > Certainly > > if ignoring this weak dependence, the yield for central collisions > > will be > > lowered, but I think that not the right thing to do. I would appreciate > > if you could show your experience in how to deal with the scale down > > factor correctly or reasonablly. > again, it might be helpful to see the histogram to which you refer. > The trigger scaledown factor is a constant for a given run, isn't it? > I guess you mean that the trigger efficiency is a function of VTX Z and > centrality (as you also say). What is the dependence, and why is the > trigger less efficient for "central" collisions? > > > > I still doubt the acceptance map. The map generated from BRAG is very > > much > > different from map generated from Claus' pure geometrical method (the > > same cut on slats of tofw is applied). And the map from BRAG for B1000 > > is > > also very much different from that for B1050. The map generated from > > BRAG > > doesn't match data at all. Then I would think it the current is wrong, > > I > > mean much lower than 1050 actally, then the acceptance correction might > > be larger, then the yield will be lower. > I do not understand this. Djamel showed a couple of weeks ago that > BRAG and CLAUS give similar results, though I do not have the mail at > hand. Again, plots would be helpful. The fact that BRAG gives much > different results for B1000 and B1050 seems to me to be impossible, if > everything is working as it should. Are you sure you are comparing > maps from these settings? How can the current be wrong? When you say > "doesn't match data at all" what do you mean? sounds like you are > comparing data and MC from different settings, but I suppose you have > checked that? > > > > I would use constructed spectra from PHENIX pi^0 spectra for pp > > collisions+Pythia simulation as reference spectrum for R_AA of pi at > > both > > mid-rapidity and forward rapidity. > Why? And how can you use PHENIX at forward rapidity? How does this > ref. compare to the one we have used for > our published results? > > > > By the way I have re-studied the RICH efficiency via simulation for > > 12A427 > > with a fiducial cut applied on track intersetion with RICH mid-plane. > > The RICH > > efficiecy for pion at pt>3GeV/c is ~97% constantly. > Thanks for some good news...:-) > And thanks for the update, > Ian > > > > > > I will update my QM04 draf on the web tomorrow. > > > > Good night! > > > > Zhongbao > > > > > > On Sun, 28 Dec 2003, flemming videbaek wrote: > > > >> As per request, we have placed the first versions as has been send to > >> us so far on > >> http://www.sdcc.bnl.gov/brahms/private/presentations/2003/QM04/ > >> index.html > >> > >> Please send comments to presenter, speakers bureau to develop these > >> talks. > >> The goal is to follow the schedule given to the presenters of > >> > >> Dec. 22: "rough draft" of talks. Please send a ppt file to the > >> including figures you know you will show, and preliminary versions of > >> figures you hope to be able to make in time to show. > >> > >> Jan 3. Final draft ppt file, together with an outline of what you plan > >> to say > >> > >> Jan 7 "final" version of talk, including reasonable suggestions > >> > >> Week of Jan 7: Give "final" talk for local group (on Friday 9 the > >> plan is to have > >> the two us talks be given at BNL) > >> > >> Jan 11: (Sunday of QM) Monday/Tuesday speakers (I believe this is > >> Ramiro and > >> Michael) give rehearsal talk for other BRAHMS people at QM. > >> (IGB) will try to organize a location for this as well as the other > >> two talks > >> > >> On behalf os the speakers bureau > >> Flemming > >> > >> > >> ---------------------------------------------------------------- > >> Flemming Videbaek > >> Physics Department > >> Brookhaven National Laboratory > >> > >> e-mail: videbaek@bnl.gov > >> phone: 631-344-4106 > > > > -- > > ----------------------------------------------------- > > Zhongbao YIN Phone: +47-55-582792 (O) > > Address: +47-55-276803 (H) > > Fantoftveien 14G 466 E-mail: > > 5075 Bergen Yin.Zhongbao@fi.uib.no > > ------------------------------------------------------ > > > > > > _______________________________________________ > > Brahms-l mailing list > > Brahms-l@lists.bnl.gov > > http://lists.bnl.gov/mailman/listinfo/brahms-l > > > > -- ----------------------------------------------------- Zhongbao YIN Phone: +47-55-582792 (O) Address: +47-55-276803 (H) Fantoftveien 14G 466 E-mail: 5075 Bergen Yin.Zhongbao@fi.uib.no ------------------------------------------------------ _______________________________________________ Brahms-l mailing list Brahms-l@lists.bnl.gov http://lists.bnl.gov/mailman/listinfo/brahms-lReceived on Mon Dec 29 13:58:56 2003
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